JP7697259B2 - Sound image control device and sound image control method - Google Patents

Description

This disclosure relates to a sound image control device and a sound image control method.

Patent document 1 discloses a method for changing the position of a specific sound source depending on the vehicle speed or the amount of pressure on the accelerator pedal.

JP 2007-10810 A

There is a need for technology that can give vehicle occupants a sense of immersion in the driving experience using a method different from that described in Patent Document 1. The present disclosure aims to provide a new technology that can give vehicle occupants a sense of immersion in the driving experience.

A sound image control device according to one aspect of the present disclosure includes an acquisition unit that acquires vehicle information related to acceleration in the longitudinal direction of the vehicle, and a sound image control unit that shifts the sound image position of the sound output from at least two speakers provided in the vehicle in the longitudinal direction of the vehicle based on the vehicle information acquired by the acquisition unit.

A sound image control device according to another aspect of the present disclosure includes an acquisition unit that acquires vehicle information related to acceleration in the left-right direction of the vehicle, and a sound image control unit that shifts the sound image position of the sound output from at least two speakers provided in the vehicle in the left-right direction of the vehicle based on the vehicle information acquired by the acquisition unit.

A sound image control method according to yet another aspect of the present disclosure is a computer-implemented sound image control method that acquires vehicle information related to acceleration in the longitudinal direction of the vehicle, and moves the sound image position of the sound output from the at least two speakers in the longitudinal direction of the vehicle based on the acquired vehicle information.

A sound image control method according to yet another aspect of the present disclosure is a computer-implemented sound image control method that acquires vehicle information related to acceleration in the left-right direction of the vehicle, and based on the acquired vehicle information, moves the sound image position of the sound output from at least two speakers equipped in the vehicle in the left-right direction of the vehicle.

1 is a diagram illustrating an example of a sound image control device 1 according to a first embodiment. FIG. 1 is a diagram illustrating an example of a vehicle 100. FIG. 13 is a diagram illustrating an example of a correspondence relationship indicated by reference information e. 11 is a diagram illustrating an example of a correspondence relationship indicated by first reference information e1. FIG. A figure showing an example of a correspondence relationship indicated by second reference information e2. FIG. 4 is a diagram showing an example of a correspondence relationship indicated by travel information g1. FIG. 11 is a diagram showing an example of a correspondence relationship indicated by sound information h1. FIG. 2 is a diagram illustrating an example of the operation of the sound image control device 1. FIG. 13 is a diagram showing an example of the relationship between forward acceleration and sound image localization in the x-axis 8a direction. 13 is a diagram showing a relationship Da between the sound pressure of the sound output from a speaker 5a and the acceleration in the forward direction, and a relationship Db between the sound pressure of the sound output from a speaker 5b and the acceleration in the forward direction. FIG. 4 is a diagram showing the sound pressure of sounds output from each of speakers 5a and 5b. FIG. FIG. 13 is a diagram showing an example of the relationship between forward acceleration and sound image localization in the x-axis 8a direction. 13 is a diagram showing a relationship Da between the sound pressure of the sound output from a speaker 5a and the acceleration in the forward direction, and a relationship Db between the sound pressure of the sound output from a speaker 5b and the acceleration in the forward direction. FIG. FIG. 13 is a diagram showing an example of the relationship between forward acceleration and sound image localization in the x-axis 8a direction. 13 is a diagram showing a relationship Da between the sound pressure of the sound output from a speaker 5a and the acceleration in the forward direction, and a relationship Db between the sound pressure of the sound output from a speaker 5b and the acceleration in the forward direction. FIG. 1 is a diagram showing an example of a vehicle 100 further including an acceleration sensor 91. FIG. 1 is a diagram showing an example of a vehicle 100 further including an acceleration sensor 92. FIG.

A: First embodiment A1: Sound image control device 1
1 is a diagram showing an example of a sound image control device 1 according to a first embodiment. The sound image control device 1 is mounted on a vehicle 100. The vehicle 100 is an electric vehicle that does not have an engine. The vehicle 100 is operated by a driver of the vehicle 100. The vehicle 100 may perform autonomous driving. The vehicle 100 includes the sound image control device 1, wheels 2a to 2d, a wheel control unit 3, a vehicle speed measurement device 3A, an operation unit 4, and speakers 5a and 5b.

Figure 2 is a diagram showing an example of a vehicle 100. In addition to the vehicle 100, Figure 2 shows an x-axis 8a along the front-rear direction of the vehicle 100, a y-axis 8b along the left-right direction of the vehicle 100, a first position i1, a second position i2, and a third position i3. The first position i1, the second position i2, and the third position i3 are aligned in the front-rear direction of the vehicle 100 (direction along the x-axis 8a). The second position i2 is located forward of the first position i1 in the front-rear direction of the vehicle 100. The third position i3 is located between the first position i1 and the second position i2 in the front-rear direction of the vehicle 100.

Vehicle 100 includes a passenger compartment 100a, a front left door 7a, a front right door 7b, a rear left door 7c, and a rear right door 7d. Passenger compartment 100a has speakers 5a and 5b, a seat 6, a portion of front left door 7a, a portion of front right door 7b, a portion of rear left door 7c, and a portion of rear right door 7d.

Each of the speakers 5a and 5b is a speaker set having multiple speakers. Each of the speakers 5a and 5b may be a single speaker. The speakers 5a and 5b are an example of at least two speakers provided in the vehicle 100. The speakers 5a and 5b emit various sounds. For example, the speakers 5a and 5b emit a virtual engine sound.

The engine sound includes the sound emitted by the engine itself, the intake sound caused by the intake of air by the engine, and the exhaust sound caused by the exhaust of air by the engine. The engine sound may be only the sound emitted by the engine itself, or it may be a combination of the sound emitted by the engine itself and the intake sound, or it may be a combination of the sound emitted by the engine itself and the exhaust sound. The engine sound may further include a sound indicative of noise.

Speaker 5a includes speakers 5a1 to 5a3. Speaker 5a1 is located in the front left door 7a. Speaker 5a2 is located in the front right door 7b. Speaker 5a3 is located in the front of the vehicle interior 100a. Each of speakers 5a, 5a1, 5a2, and 5a3 is an example of a first speaker.

Speaker 5b is located rearward of speaker 5a in the fore-and-aft direction of vehicle 100. Speaker 5b has speakers 5b1 to 5b3. Speaker 5b1 is located in the rear left door 7c. Speaker 5b2 is located in the rear right door 7d. Speaker 5b3 is located at the rear of passenger compartment 100a. Each of speakers 5b, 5b1, 5b2, and 5b3 is an example of a second speaker.

The sound image control device 1 shown in FIG. 1 causes the speakers 5a and 5b to emit virtual engine sounds. The sound image control device 1 moves the sound image localization of the sounds output from the speakers 5a and 5b in the front-to-rear direction of the vehicle 100. The sound image is the sound source perceived by the person who hears the sounds output from the speakers 5a and 5b. Sound image localization means the position of the sound image. In this embodiment, sound is localized for any or all of the passengers seated in the seat 6 by causing the speakers 5a and 5b to emit sound. Note that the driver (passenger) seated in the driver's seat may be the only target of the sound image localization.

Each of the wheels 2a and 2b is a front wheel of the vehicle 100. Each of the wheels 2c and 2d is a rear wheel of the vehicle 100. The vehicle 100 may have additional wheels in addition to the wheels 2a-2d.

The wheel control unit 3 controls the rotation of each of the wheels 2a and 2b. The wheel control unit 3 may control the rotation of each of the wheels 2c and 2d instead of the rotation of each of the wheels 2a and 2b. The wheel control unit 3 may control the rotation of each of the wheels 2a to 2d. The wheel control unit 3 includes a motor 31, an accelerator pedal 32, a shift lever 33, a motor control unit 34, and a power transmission unit 35.

The motor 31 generates power based on electric power. The accelerator pedal 32 and the shift lever 33 are each operated by the driver of the vehicle 100. The accelerator pedal 32 and the shift lever 33 may each be operated automatically.

The position of the accelerator pedal 32 is adjusted by the driver of the vehicle 100. The position of the accelerator pedal 32 corresponds to the "accelerator opening". The accelerator opening increases as the difference between the position of the accelerator pedal 32 and the reference position of the accelerator pedal 32 increases. The accelerator opening decreases as the difference between the position of the accelerator pedal 32 and the reference position of the accelerator pedal 32 decreases. The reference position of the accelerator pedal 32 is the position of the accelerator pedal 32 when the accelerator pedal 32 is not being operated. When the position of the accelerator pedal 32 matches the reference position of the accelerator pedal 32, the accelerator opening is "0".

The difference between the position of the accelerator pedal 32 and the reference position of the accelerator pedal 32 can be referred to as the "displacement amount of the accelerator pedal 32." The displacement amount of the accelerator pedal 32 may be used as the opening degree of the accelerator.

The accelerator pedal 32 is an example of an accelerator. If the vehicle 100 has an accelerator lever instead of the accelerator pedal 32, the accelerator lever is an example of an accelerator.

The shift lever 33 is selectively set to one of the drive range, parking range, reverse range, and neutral range by the driver of the vehicle 100.

The motor control unit 34 detects the position of the accelerator pedal 32 and the position of the shift lever 33. Methods for detecting the position of the accelerator pedal 32 and the position of the shift lever 33 are well known, so detailed explanations will be omitted.

The motor control unit 34 controls the motor 31 based on the position of the accelerator pedal 32 and the position of the shift lever 33. For example, the motor control unit 34 generates rotation direction information and rotation speed information based on the position of the accelerator pedal 32 and the position of the shift lever 33. The rotation direction information is information that determines the rotation direction of the motor 31. The rotation speed information is information that determines the rotation speed of the motor 31. The motor control unit 34 sets the rotation direction of the motor 31 to the rotation direction determined by the rotation direction information. The motor control unit 34 sets the rotation speed of the motor 31 to the rotation speed determined by the rotation speed information. The method of controlling the rotation (rotation direction and rotation speed) of the motor 31 based on the position of the accelerator pedal 32 and the position of the shift lever 33 is publicly known, so a detailed description will be omitted.

The power transmission unit 35 is a set of reduction gears. The power transmission unit 35 transmits the power generated by the motor 31 to the wheels 2a and 2b. The power transmission unit 35 may transmit the power generated by the motor 31 to the wheels 2c and 2d instead of the wheels 2a and 2b. The power transmission unit 35 may transmit the power generated by the motor 31 to the wheels 2a to 2d.

The speed measuring device 3A measures the speed of the vehicle 100. The speed measuring device 3A generates speed information a1 based on the measurement result of the speed of the vehicle 100. The speed information a1 is information indicating the speed of the vehicle 100. A change in the speed information a1 indicates the degree of acceleration in the forward/rearward direction of the vehicle 100. Therefore, the speed information a1 is an example of information that determines the degree of acceleration in the forward/rearward direction of the vehicle 100.

The information determining the degree of acceleration in the fore-and-aft direction of the vehicle 100 may include information specifying the degree of acceleration in the fore-and-aft direction of the vehicle 100. The information determining the degree of acceleration in the fore-and-aft direction of the vehicle 100 is an example of vehicle information related to acceleration in the fore-and-aft direction of the vehicle 100. The vehicle information related to acceleration in the fore-and-aft direction of the vehicle 100 is not limited to information determining the degree of acceleration in the fore-and-aft direction of the vehicle 100. The vehicle information related to acceleration in the fore-and-aft direction of the vehicle 100 may be information indicating the degree of acceleration in the fore-and-aft direction of the vehicle 100 (for example, information indicating the acceleration in the fore-and-aft direction of the vehicle 100). Vehicle information related to acceleration is a concept that encompasses information determining the degree of acceleration and information indicating the degree of acceleration.

The motor control unit 34 generates accelerator information b1 based on the position of the accelerator pedal 32. The accelerator information b1 is information that indicates the opening degree of the accelerator.

The operation unit 4 is, for example, a touch panel. The operation unit 4 is not limited to a touch panel, and may be an operation panel having various operation buttons. The operation unit 4 receives operations performed by a passenger of the vehicle 100. Hereinafter, the "passenger of the vehicle 100" will be simply referred to as the "passenger".

The sound image control device 1 includes a memory device 11 and a processing device 12. The memory device 11 may be an external element of the sound image control device 1.

The storage device 11 is a recording medium that can be read by a computer (e.g., a non-transitive recording medium that can be read by a computer). The storage device 11 includes a non-volatile memory and a volatile memory. The non-volatile memory is, for example, a ROM (Read Only Memory), an EPROM (Erasable Programmable Read Only Memory), and an EEPROM (Electrically Erasable Programmable Read Only Memory). The volatile memory is, for example, a RAM (Random Access Memory).

The storage device 11 stores a program p1 and various information. The program p1 defines the operation of the sound image control device 1. The storage device 11 may store the program p1 read from a storage device in a server (not shown). In this case, the storage device in the server is an example of a recording medium readable by a computer.

The processing device 12 includes one or more central processing units (CPUs). The one or more CPUs are an example of one or more processors. Each of the processing device, processor, and CPU is an example of a computer.

The processing device 12 reads the program p1 from the storage device 11. The processing device 12 executes the program p1 to function as an acquisition unit 13, a generation unit 14, and a sound image control unit 15. At least one of the acquisition unit 13, the generation unit 14, and the sound image control unit 15 may be realized by a circuit such as a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

The acquisition unit 13 acquires the speed information a1 from the vehicle speed measurement device 3A. For example, the acquisition unit 13 first transmits a request for the speed information a1 to the vehicle speed measurement device 3A. The acquisition unit 13 acquires the speed information a1 transmitted from the vehicle speed measurement device 3A in response to the request for the speed information a1. When the vehicle speed measurement device 3A actively transmits the speed information a1 to the acquisition unit 13, the acquisition unit 13 may acquire the speed information a1 actively transmitted from the vehicle speed measurement device 3A. The acquisition unit 13 acquires the accelerator information b1 from the motor control unit 34. For example, the acquisition unit 13 first transmits a request for the accelerator information b1 to the motor control unit 34. The acquisition unit 13 acquires the accelerator information b1 transmitted from the motor control unit 34 in response to the request for the accelerator information b1. When the motor control unit 34 actively transmits the accelerator information b1 to the acquisition unit 13, the acquisition unit 13 may acquire the accelerator information b1 actively transmitted from the motor control unit 34. The speed information a1 and the accelerator information b1 are communicated via a controller area network (CAN). The speed information a1 and the accelerator information b1 may be communicated using a communication protocol different from CAN.

The generation unit 14 generates a sound signal c1 based on the speed information a1 and accelerator information b1 acquired by the acquisition unit 13. The sound signal c1 is a surround signal that indicates a virtual engine sound. The generation unit 14 includes a determination unit 141 and a signal generation unit 142.

The determination unit 141 determines the rotation speed of the virtual engine based on the speed information a1. The virtual engine is a virtual engine virtually installed in the vehicle 100. The determination unit 141 determines the rotation speed of the virtual engine by using the reference information e.

The reference information e is information that indicates the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine. The reference information e is stored in the storage device 11.

The determination unit 141 uses the reference information e to determine the rotation speed of the virtual engine corresponding to the speed of the vehicle 100 indicated by the speed information a1. When the determination unit 141 determines the rotation speed of the virtual engine, it generates rotation speed information f1 indicating the rotation speed of the virtual engine.

The reference information e may include first reference information e1 and second reference information e2. The first reference information e1 is information indicating the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine when the vehicle 100 is accelerating. The second reference information e2 is information indicating the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine when the vehicle 100 is decelerating and when the vehicle 100 is at a constant speed.

Even if the reference information e includes the first reference information e1 and the second reference information e2, the determination unit 141 determines the rotation speed of the virtual engine based on the speed information a1.

For example, the determination unit 141 first determines whether the vehicle 100 is accelerating based on the change in the speed information a1.

When the determination unit 141 determines that the vehicle 100 is accelerating, it uses the first reference information e1 to determine the virtual engine speed corresponding to the speed of the vehicle 100 indicated by the speed information a1.

When the determination unit 141 determines that the vehicle 100 is not accelerating, it determines that the vehicle 100 is decelerating or at a constant speed.

When the determination unit 141 determines that the vehicle 100 is decelerating or moving at a constant speed, it uses the second reference information e2 to determine the virtual engine speed corresponding to the speed of the vehicle 100 indicated by the speed information a1.

Even when the reference information e includes the first reference information e1 and the second reference information e2, when the determination unit 141 determines the rotation speed of the virtual engine, it generates rotation speed information f1 indicating the rotation speed of the virtual engine.

The signal generator 142 generates a sound signal c1 based on the rotation speed information f1 and the accelerator information b1.

The signal generating unit 142 first determines the running state of the vehicle 100 based on the rotation speed information f1 and the accelerator information b1. For example, the signal generating unit 142 determines the running state of the vehicle 100 by using the running information g1.

The driving information g1 is information that indicates the correspondence between the rotation speed of the virtual engine, the accelerator opening, and the driving state of the vehicle 100. The driving information g1 is stored in the storage device 11.

The signal generating unit 142 uses the driving information g1 to determine the driving state of the vehicle 100 that corresponds to both the virtual engine RPM indicated by the RPM information f1 and the accelerator opening indicated by the accelerator information b1.

Then, the signal generating unit 142 generates a sound signal c1 based on the traveling state of the vehicle 100. For example, the signal generating unit 142 generates the sound signal c1 by using the sound information h1.

The sound information h1 is information indicating the correspondence between the running state of the vehicle 100 and sound data indicating a virtual engine sound. The sound data indicates a virtual engine sound corresponding to the running state of the vehicle 100. The sound information h1 is stored in the storage device 11.

The signal generating unit 142 uses the sound information h1 to generate a sound signal c1 corresponding to the running state of the vehicle 100.

The sound signal c1 is a multi-channel sound signal. The sound signal c1 includes a sound signal c1a for the speaker 5a and a sound signal c1b for the speaker 5b. Each of the sound signals c1a and c1b is a multi-channel sound signal. When the speaker 5a is a single speaker, the sound signal c1a is a single-channel sound signal. When the speaker 5b is a single speaker, the sound signal c1b is a single-channel sound signal.

The sound image control unit 15 moves the sound image localization of the sound output from the speakers 5a and 5b in the forward/rearward direction of the vehicle 100 based on the speed information a1 acquired by the acquisition unit 13. For example, the sound image control unit 15 generates acceleration information based on the speed information a1. The acceleration information indicates the acceleration of the vehicle 100. The sound image control unit 15 moves the sound image localization of the sound output from the speakers 5a and 5b in the forward/rearward direction of the vehicle 100 based on the acceleration information.

The sound image control unit 15 generates a sound signal c2a for the speaker 5a by adjusting the amplitude of the sound signal c1a based on the acceleration information. The sound image control unit 15 generates a sound signal c2b for the speaker 5b by adjusting the amplitude of the sound signal c1b based on the acceleration information.

Each of the sound signals c2a and c2b is a multi-channel sound signal. When the speaker 5a is a single speaker, the sound signal c2a is a single-channel sound signal. When the speaker 5b is a single speaker, the sound signal c2b is a single-channel sound signal.

The sound image control unit 15 provides the sound signal c2a to the speaker 5a. The sound image control unit 15 provides the sound signal c2b to the speaker 5b. The sound signals c2a and c2b affect the sound image positioning of the sounds output from the speakers 5a and 5b.

A2: Reference information e
The reference information e indicates the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine. The rotation speed of the virtual engine depends on the speed of the vehicle 100 and the virtual transmission.

The virtual transmission is a transmission that is virtually installed in the vehicle 100. The virtual transmission has three gears, J1 to J3. Gear J1 corresponds to first gear in the virtual transmission. Gear J2 corresponds to second gear in the virtual transmission. Gear J3 corresponds to third gear in the virtual transmission. Each of gears J1, J2, and J3 may also be referred to as a shift gear. The virtual transmission may have one or more gears.

Figure 3 is a diagram showing an example of the correspondence indicated by reference information e, that is, a diagram showing an example of the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine. In Figure 3, the horizontal axis shows the speed of the vehicle 100, and the vertical axis shows the rotation speed of the virtual engine.

Reference information e indicates the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine for each of the gears J1 to J3. The rotation speed MAX1 of the virtual engine indicates the maximum rotation speed of the virtual engine. The maximum rotation speed of the virtual engine is, for example, 9000 rpm (revolutions per minute). The maximum rotation speed of the virtual engine is not limited to 9000 rpm.

The reference information e includes first reference information e1 and second reference information e2. The first reference information e1 is information indicating the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine when the vehicle 100 is accelerating. The second reference information e2 is information indicating the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine when the vehicle 100 is decelerating and at a constant speed.

Figure 4 is a diagram showing an example of the correspondence indicated by the first reference information e1, that is, a diagram showing an example of the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine when the vehicle 100 is accelerating. In Figure 4, the horizontal axis shows the speed of the vehicle 100, and the vertical axis shows the rotation speed of the virtual engine.

The first reference information e1 indicates the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine for gear J1 as the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine when the speed of the vehicle 100 is less than speed V1.

Speed V1 is the speed of the vehicle 100 when the rotation speed of the virtual engine using gear J1 reaches rotation speed MAX1. Speed V1 may be smaller than the speed of the vehicle 100 when the rotation speed of the virtual engine using gear J1 reaches rotation speed MAX1.

The first reference information e1 indicates the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine for gear J2 as the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine when the speed of the vehicle 100 is equal to or greater than speed V1 and less than speed V2.

Speed V2 is the speed of the vehicle 100 when the rotation speed of the virtual engine using gear J2 reaches rotation speed MAX1. Speed V2 may be a speed that is smaller than the speed of the vehicle 100 when the rotation speed of the virtual engine using gear J2 reaches rotation speed MAX1 and greater than speed V1.

The first reference information e1 indicates the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine for gear J3 as the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine when the speed of the vehicle 100 is equal to or greater than speed V2.

Figure 5 is a diagram showing an example of the correspondence indicated by the second reference information e2, that is, a diagram showing an example of the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine when the vehicle 100 is decelerating and at a constant speed. In Figure 5, the horizontal axis shows the speed of the vehicle 100, and the vertical axis shows the rotation speed of the virtual engine.

The second reference information e2 indicates the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine for gear J3 as the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine when the speed of the vehicle 100 is greater than speed V4. Speed V4 is greater than speed V1 and less than speed V2.

The second reference information e2 indicates the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine for gear J2 as the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine when the speed of the vehicle 100 is greater than speed V3 and less than speed V4. Speed V3 is greater than or equal to 0 and less than speed V1.

The second reference information e2 indicates the correspondence relationship between the speed of the vehicle 100 and the rotation speed of the virtual engine for gear J1 when the speed of the vehicle 100 is equal to or lower than speed V3.

A3: Travel information g1
The driving information g1 indicates the correspondence between the rotation speed of the virtual engine, the accelerator opening, and the driving state of the vehicle 100.

Figure 6 is a diagram showing an example of the correspondence indicated by the driving information g1. In Figure 6, the horizontal axis indicates the virtual engine RPM, and the vertical axis indicates the accelerator opening. The driving state of the vehicle 100 is divided into regions K1 to K25 according to the virtual engine RPM and the accelerator opening. Hereinafter, when there is no need to distinguish between the regions K1 to K25, each of the regions K1 to K25 will be referred to as "region K". The number of regions K is not limited to 25, and may be a number smaller than 25 or a number larger than 25.

A4: Sound information h1
The sound information h1 is information indicating the correspondence between the running state of the vehicle 100 and sound data indicating a virtual engine sound corresponding to the running state of the vehicle 100.

Figure 7 is a diagram showing an example of the correspondence indicated by the sound information h1. The sound information h1 indicates the correspondence between the areas K1 to K25 indicating the traveling state of the vehicle 100 and the sound data M1 to M25 defining the sound signal.

Sound data M1 to M25 correspond one-to-one to regions K1 to K25. For example, sound data M1 corresponds to region K1, and sound data M25 corresponds to region K25. Sound data M1 to M25 are mutually different. Hereinafter, when there is no need to distinguish between sound data M1 to M25, each of sound data M1 to M25 will be referred to as "sound data M."

The sound data M indicates a virtual engine sound corresponding to the corresponding area K (the driving state of the corresponding vehicle 100). The sound data M indicates a sound that imitates the engine sound of an engine that actually exists. The sound data M may also indicate the engine sound of a fictitious engine.

A5: Description of Operation Fig. 8 is a diagram showing an example of the operation of the sound image control device 1. In the following, it is assumed that the vehicle speed measurement device 3A generates speed information a1 indicating the speed of the vehicle 100. It is assumed that the motor control unit 34 generates accelerator information b1 indicating the accelerator opening. It is assumed that the reference information e indicating the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine includes the first reference information e1 shown in Fig. 4 and the second reference information e2 shown in Fig. 5.

When the operation unit 4 receives a generation operation from the passenger instructing the generation of the sound signal c1, the operation shown in FIG. 8 starts. The operation shown in FIG. 8 is repeated until the operation unit 4 receives an end operation from the passenger instructing the end of the generation of the sound signal c1.

In step S101, the acquisition unit 13 acquires speed information a1 from the vehicle speed measurement device 3A and accelerator information b1 from the motor control unit 34.

Next, in step S102, the acquisition unit 13 stores the speed information a1 in the storage device 11. As a result, the history of the speed information a1 is stored in the storage device 11.

The history of the speed information a1 remains in the storage device 11 until the operation unit 4 receives a termination operation from the passenger. When the operation unit 4 receives a termination operation from the passenger, the acquisition unit 13 deletes the history of the speed information a1 from the storage device 11. Therefore, the history of the speed information a1 is not stored in the storage device 11 at the time the operation unit 4 receives a generation operation from the passenger.

When the acquisition unit 13 stores the speed information a1 in the storage device 11, it provides the speed information a1 to the determination unit 141. In addition, the acquisition unit 13 provides the accelerator information b1 to the signal generation unit 142.

Next, in step S103, the decision unit 141 determines whether the vehicle 100 is accelerating based on the change in the speed information a1.

In step S103, the decision unit 141 determines whether the speed of the vehicle 100 is increasing (whether it is accelerating) by referring to the history of the speed information a1.

For example, the determination unit 141 first identifies the speed information a1 stored in the current step S102 and the speed information a1 stored in the previous step S102 from the history of the speed information a1. If the speed information a1 stored in the previous step S102 does not exist in the storage device 11, the determination unit 141 uses "0" as the speed of the vehicle 100 indicated by the speed information a1 stored in the previous step S102.

The decision unit 141 then determines whether the speed of the vehicle 100 indicated by the speed information a1 stored in the current step S102 is greater than the speed of the vehicle 100 indicated by the speed information a1 stored in the previous step S102. An increase in the speed of the vehicle 100 means that the vehicle 100 is accelerating. Therefore, determining whether the speed of the vehicle 100 is increasing means determining whether the vehicle 100 is accelerating.

The determination unit 141 determines that the vehicle 100 is accelerating if the speed of the vehicle 100 indicated by the speed information a1 stored in the current step S102 is greater than the speed of the vehicle 100 indicated by the speed information a1 stored in the previous step S102.

When the determination unit 141 determines in step S103 that the vehicle 100 is accelerating, in step S104 it determines the rotation speed of the virtual engine by using the first reference information e1.

In step S104, the determination unit 141 first determines, from among the virtual engine revolutions indicated in the first reference information e1, the virtual engine revolutions corresponding to the speed of the vehicle 100 indicated by the speed information a1 as the revolutions during acceleration. Next, the determination unit 141 determines the revolutions during acceleration as the revolutions of the virtual engine.

For example, when the vehicle 100 is accelerating and the speed of the vehicle 100 is less than speed V1, the determination unit 141 first selects the correspondence between the speed of the vehicle 100 and the rotation speed of the virtual engine for the gear J1 indicated in the first reference information e1. Next, the determination unit 141 determines, from the rotation speeds of the virtual engine indicated for the gear J1, the rotation speed of the virtual engine that corresponds to the speed of the vehicle 100 indicated by the speed information a1 as the rotation speed during acceleration. Next, the determination unit 141 determines the rotation speed during acceleration as the rotation speed of the virtual engine.

If the determination unit 141 determines in step S103 that the vehicle 100 is not accelerating, it determines that the vehicle 100 is decelerating or at a constant speed. Next, in step S105, the determination unit 141 determines the rotation speed of the virtual engine using the second reference information e2.

In step S105, the determination unit 141 first identifies, from among the virtual engine RPMs indicated in the second reference information e2, the virtual engine RPM that corresponds to the speed of the vehicle 100 indicated by the speed information a1 as the relevant RPM. Next, the determination unit 141 determines the relevant RPM as the virtual engine RPM.

When the rotation speed of the virtual engine is determined in step S104 or step S105, the determination unit 141 generates rotation speed information f1 indicating the rotation speed of the virtual engine in step S106. The determination unit 141 provides the rotation speed information f1 to the signal generation unit 142.

Next, in step S107, the signal generation unit 142 determines the driving state of the vehicle 100 based on the rotation speed information f1 and the accelerator information b1.

In step S107, the signal generating unit 142 uses the rotation speed information f1, accelerator information b1, and driving information g1 to determine the driving state of the vehicle 100. The regions K1 to K25 indicated in the driving information g1 indicate the driving state of the vehicle 100. The signal generating unit 142 determines, from among the regions K1 to K25 indicated in the driving information g1, the region K that corresponds to both the rotation speed of the virtual engine indicated by the rotation speed information f1 and the accelerator opening indicated by the accelerator information b1, as the driving state of the vehicle 100.

Next, in step S108, the signal generating unit 142 generates a sound signal c1 based on the driving state of the vehicle 100.

In step S108, the signal generating unit 142 generates a sound signal c1 using the running state of the vehicle 100 and the sound information h1. The signal generating unit 142 first reads out, as the relevant sound data, sound data M corresponding to the region K determined as the running state of the vehicle 100 from among the sound data M1 to M25 indicated in the sound information h1. The signal generating unit 142 then generates a sound signal c1 indicating the sound indicated by the relevant sound data in multiple channels. The sound signal c1 includes a sound signal c1a for the speaker 5a and a sound signal c1b for the speaker 5b. The signal generating unit 142 then provides the sound signal c1 (sound signals c1a and c1b) to the sound image control unit 15.

Next, in step S109, the sound image control unit 15 controls the sound image positioning of the sound output by the speakers 5a and 5b based on the acceleration information.

In step S109, the sound image control unit 15 first determines the acceleration of the vehicle 100 in the forward direction based on the speed information a1. Hereinafter, the acceleration of the vehicle 100 in the forward direction is referred to as the "forward acceleration." The sound image control unit 15 determines acceleration information indicating the forward acceleration using the history of the speed information a1 stored in the storage device 11.

For example, the sound image control unit 15 first identifies the speed information a1 stored in the current step S102 as speed information a1A. Next, the sound image control unit 15 identifies the speed information a1 stored in the previous step S102 as speed information a1B. Next, the sound image control unit 15 identifies the speed difference by subtracting the speed of the vehicle 100 indicated by the speed information a1B from the speed of the vehicle 100 indicated by the speed information a1A. Next, the sound image control unit 15 generates acceleration information indicating the acceleration in the forward direction by dividing the speed difference by the time between the execution of the current step S102 and the execution of the previous step S102. If the speed information a1 stored in the previous step S102 does not exist in the storage device 11, the sound image control unit 15 uses "0" as the speed of the vehicle 100 indicated by the speed information a1B.

If the speed of the vehicle 100 indicated by the speed information a1A is greater than the speed of the vehicle 100 indicated by the speed information a1B, the speed information a1A indicates forward acceleration. If the speed of the vehicle 100 indicated by the speed information a1A is not greater than the speed of the vehicle 100 indicated by the speed information a1B, the speed information a1A does not indicate forward acceleration of the vehicle 100.

When the forward acceleration is a positive value, the sound image control unit 15 sets the sound image localization of the sound output from the speakers 5a and 5b based on the forward acceleration. For example, the sound image control unit 15 sets the sound image localization when the speed information a1A indicates forward acceleration of the vehicle 100 to a position further forward than the sound image localization when the speed information a1A does not indicate forward acceleration of the vehicle 100.

The smaller the forward acceleration, the closer the sound image control unit 15 moves the sound image localization to the first position i1.The larger the forward acceleration, the closer the sound image control unit 15 moves the sound image localization to the second position i2.

Figure 9 is a diagram showing an example of the relationship between forward acceleration and sound image localization (position of the sound image) in the direction of the x-axis 8a. The relationship between forward acceleration and sound image localization in the direction of the x-axis 8a is not limited to the relationship shown in Figure 9. For example, the smaller the forward acceleration, the closer the sound image localization may be to the first position i1 in a stepwise manner. The greater the forward acceleration, the closer the sound image localization may be to the second position i2 in a stepwise manner.

The sound image control unit 15 controls the amplitude of the sound signal c2a and the amplitude of the sound signal c2b based on the forward acceleration, thereby shifting the sound image position of the sound output by the speakers 5a and 5b in the fore-and-aft direction of the vehicle 100. Controlling the amplitude of the sound signal c2a and the amplitude of the sound signal c2b based on the forward acceleration is an example of controlling the sound pressure of the sound output by the first speaker and the sound pressure of the sound output by the second speaker based on vehicle information.

The sound image control unit 15, for example, moves the sound image position in the fore-and-aft direction of the vehicle 100 by changing the magnitude relationship between the sound pressure of the sound output by the speaker 5a and the sound pressure of the sound output by the speaker 5b.

Figure 10 shows the relationship Da between the sound pressure of the sound output by speaker 5a and the forward acceleration, and the relationship Db between the sound pressure of the sound output by speaker 5b and the forward acceleration.

The smaller the forward acceleration, the smaller the amplitude of the sound signal c2a is made by the sound image control unit 15. Therefore, the smaller the forward acceleration, the smaller the sound pressure of the sound output by the speaker 5a located at the front of the vehicle 100 is made by the sound image control unit 15.

The smaller the forward acceleration, the larger the amplitude of the sound signal c2b is made by the sound image control unit 15. Therefore, the smaller the forward acceleration, the larger the sound pressure of the sound output by the speaker 5b located at the rear of the vehicle 100 is made by the sound image control unit 15.

The greater the forward acceleration, the greater the amplitude of the sound signal c2a that the sound image control unit 15 increases. Therefore, the greater the forward acceleration, the greater the sound pressure that the sound image control unit 15 increases that the speaker 5a located at the front of the vehicle 100 outputs.

The greater the forward acceleration, the smaller the amplitude of the sound signal c2b is made by the sound image control unit 15. Therefore, the greater the forward acceleration, the smaller the sound pressure of the sound output by the speaker 5b located at the rear of the vehicle 100 is made by the sound image control unit 15.

The speaker 5a outputs the virtual engine sound represented by the sound signal c2a at a sound pressure according to the amplitude of the sound signal c2a. The speaker 5b outputs the virtual engine sound represented by the sound signal c2b at a sound pressure according to the amplitude of the sound signal c2b. Therefore, the passenger can recognize a sound image that moves back and forth according to the degree of acceleration of the vehicle 100.

Then, the operation shown in FIG. 8 is repeated until the operation unit 4 receives a termination operation from the passenger.

A6: Summary of the First Embodiment The sound image control unit 15 sets the sound image localization when the speed information a1A indicates forward acceleration of the vehicle 100 to a position that is further forward than the sound image localization when the speed information a1A does not indicate forward acceleration of the vehicle 100. When the vehicle 100 accelerates forward, the passenger receives a force toward the rear of the vehicle 100. Therefore, when the vehicle 100 accelerates forward, the passenger feels that the sound image is moving forward of the vehicle 100 in a state in which the passenger receives a force toward the rear of the vehicle 100. Therefore, compared to when the sound image does not move forward of the vehicle 100, the passenger is more likely to feel that he or she is being pushed toward the rear of the vehicle 100 as the vehicle 100 accelerates forward. Therefore, the passenger can feel immersed in the driving.

B: Modifications Modifications of the first embodiment are shown below. Two or more aspects arbitrarily selected from the following aspects may be appropriately combined as long as they are not mutually contradictory.

B1: First Modified Example In the first embodiment, the sound image control unit 15 may move the sound image positioning in the fore-and-aft direction of the vehicle 100 without changing the magnitude relationship between the sound pressure of the sound output by the speaker 5a and the sound pressure of the sound output by the speaker 5b.

For example, the sound image control unit 15 controls the sound pressure of the sound output by the speaker 5a and the sound pressure of the sound output by the speaker 5b as shown in FIG. 11. The sound image control unit 15 realizes the relationship Da and the relationship Db shown in FIG. 11 by controlling the amplitude of the sound signal c2a and the amplitude of the sound signal c2b based on the acceleration in the forward direction. Note that the second position i2 in the first modified example is located further rearward than the second position i2 in the first embodiment.

According to the first modified example, the sound image control unit 15 can move the sound image forward of the vehicle 100, for example, without adjusting the sound pressure of the sound output by the speaker 5b.

B2: Second Modification In the first embodiment and the first modification, the sound image control unit 15 may set the sound image positioning of the sound output by the speakers 5a and 5b based on the forward acceleration, even when the forward acceleration is a negative value (when the vehicle 100 is decelerating).

Figure 12 is a diagram showing an example of the relationship between forward acceleration and sound image localization (position of the sound image) in the x-axis 8a direction. When the forward acceleration is "0", the sound image control unit 15 sets the sound image localization of the sound output by the speakers 5a and 5b to the third position i3. The smaller the forward acceleration, the closer the sound image control unit 15 moves the sound image localization of the sound output by the speakers 5a and 5b to the first position i1. The greater the forward acceleration, the closer the sound image control unit 15 moves the sound image localization of the sound output by the speakers 5a and 5b to the second position i2.

The relationship between the forward acceleration and the sound image localization (position of the sound image) in the x-axis 8a direction is not limited to the relationship shown in FIG. 12. For example, the smaller the forward acceleration, the closer the sound image localization may be to the first position i1 in a stepwise manner. The larger the forward acceleration, the closer the sound image localization may be to the second position i2 in a stepwise manner.

For example, the sound image control unit 15 changes the magnitude relationship between the sound pressure of the sound output by the speaker 5a and the sound pressure of the sound output by the speaker 5b, thereby shifting the sound image position of the sound output by the speakers 5a and 5b in the forward/rearward direction of the vehicle 100.

Figure 13 shows the relationship Da between the sound pressure of the sound output by speaker 5a and the forward acceleration, and the relationship Db between the sound pressure of the sound output by speaker 5b and the forward acceleration. The sound image control unit 15 realizes the relationships Da and Db shown in Figure 13 by controlling the amplitude of sound signal c2a and the amplitude of sound signal c2b based on the forward acceleration.

According to the second modification, when the vehicle 100 is decelerating, the passenger feels as if the sound image is moving. This allows the passenger to feel immersed in the ride.

B3: Third Modification In the first embodiment, the sound image control unit 15 may set the sound image localization when the speed information a1A indicates forward acceleration of the vehicle 100 to a position further rearward of the vehicle 100 than the sound image localization when the speed information a1A does not indicate forward acceleration of the vehicle 100.

The smaller the forward acceleration, the closer the sound image control unit 15 brings the sound image position of the sound output from the speakers 5a and 5b to the second position i2.The larger the forward acceleration, the closer the sound image control unit 15 brings the sound image position of the sound output from the speakers 5a and 5b to the first position i1.

Figure 14 is a diagram showing an example of the relationship between forward acceleration and sound image localization (position of the sound image) in the x-axis 8a direction. The relationship between forward acceleration and sound image localization in the x-axis 8a direction is not limited to the relationship shown in Figure 14. The smaller the forward acceleration, the closer the sound image localization may be to the second position i2 in a stepwise manner. The greater the forward acceleration, the closer the sound image localization may be to the first position i1 in a stepwise manner.

Figure 15 shows the relationship Da between the sound pressure of the sound output by speaker 5a and the forward acceleration, and the relationship Db between the sound pressure of the sound output by speaker 5b and the forward acceleration.

The smaller the forward acceleration, the greater the amplitude of the sound signal c2a provided to the speaker 5a located at the front of the vehicle 100, the more the sound image control unit 15 increases the sound pressure of the sound output by the speaker 5a located at the front of the vehicle 100.

The smaller the forward acceleration, the smaller the sound image control unit 15 reduces the amplitude of the sound signal c2b provided to the speaker 5b located at the rear of the vehicle 100. Therefore, the smaller the forward acceleration, the smaller the sound image control unit 15 reduces the sound pressure of the sound output by the speaker 5b located at the rear of the vehicle 100.

The greater the forward acceleration, the smaller the amplitude of the sound signal c2a provided to the speaker 5a located at the front of the vehicle 100, the more the sound image control unit 15 reduces the sound pressure of the sound output by the speaker 5a located at the front of the vehicle 100.

The greater the forward acceleration, the greater the sound image control unit 15 increases the amplitude of the sound signal c2b provided to the speaker 5b located at the rear of the vehicle 100. Therefore, the greater the forward acceleration, the greater the sound image control unit 15 increases the sound pressure of the sound output by the speaker 5b located at the rear of the vehicle 100.

In the third modified example, the sound image control unit 15 may also move the sound image position in the fore-and-aft direction of the vehicle 100 without changing the magnitude relationship between the sound pressure of the sound output by the speaker 5a and the sound pressure of the sound output by the speaker 5b.

According to the third modified example, the passenger can recognize a sound image that moves backward as the acceleration of the vehicle 100 increases. When the vehicle 100 accelerates forward, the passenger receives a force toward the rear of the vehicle 100. Therefore, when the vehicle 100 accelerates forward, the passenger gets the sensation that the sound image is moving toward the rear of the vehicle 100 in a state in which the passenger receives a force toward the rear of the vehicle 100. Therefore, compared to a case in which the sound image does not move, the passenger may be more likely to get the sensation that he or she is moving toward the rear of the vehicle 100 together with the sound image as the vehicle 100 accelerates forward. Therefore, the passenger can get a sense of immersion in the driving.

B4: Fourth Modification In the first embodiment and the first to third modifications, the sound image control unit 15 may change the position of the sound image by executing a sound image localization process as shown in the above-mentioned Patent Document 1.

In the sound image localization process, the sound image control unit 15 operates, for example, as follows. The sound image control unit 15 uses the sound transfer function (head-related transfer function: HRTF) in the space from a sound source located at the position of the target sound image to the passenger's ears. The sound image control unit 15 generates sound signals c2a and c2b by performing convolution processing based on the sound transfer function on the sound signal c1.

When the sound image control unit 15 changes the position of the sound image by the sound image localization process, the sound image localization can be moved in the fore-and-aft direction of the vehicle 100, regardless of the relative positions of the speakers 5a and 5b. Therefore, when the sound image control unit 15 changes the position of the sound image by the sound image localization process, the speaker 5b does not have to be located behind the speaker 5a. For example, the speaker 5b may be located to the right or left of the speaker 5a. Also, even if the speakers 5a and 5b are located in the same positions as those shown in the first embodiment and the first to third modified examples, the sound image can be localized, for example, further forward than the second position i2.

According to the fourth modification, the position of the sound image can be moved in the fore-and-aft direction of the vehicle 100 regardless of the relative positions of the speakers 5a and 5b.

B5: Fifth Modification In the first embodiment and the first to fourth modifications, the vehicle 100 may have an acceleration sensor 91 that detects acceleration in the forward direction.

Figure 16 is a diagram showing an example of a vehicle 100 that further includes an acceleration sensor 91. The acquisition unit 13 acquires the output of the acceleration sensor 91, i.e., information indicating acceleration in the forward direction. The sound image control unit 15 may determine the acceleration in the forward direction using the output of the acceleration sensor 91 acquired by the acquisition unit 13 instead of the speed information a1. The output of the acceleration sensor 91 is another example of vehicle information related to acceleration in the forward/backward direction of the vehicle 100. The output of the acceleration sensor 91 is also an example of information indicating the degree of acceleration in the forward/backward direction of the vehicle 100.

The generation unit 14 may use the output of the acceleration sensor 91 instead of the speed information a1. For example, the generation unit 14 determines whether the vehicle 100 is accelerating based on the output of the acceleration sensor 91. Furthermore, instead of indicating the correspondence between the rotation speed of the virtual engine, the accelerator opening, and the driving state of the vehicle 100, the driving information g1 indicates the correspondence between the rotation speed of the virtual engine, the output of the acceleration sensor 91, and the driving state of the vehicle 100. The generation unit 14 determines the driving state of the vehicle 100 using the driving information g1, the rotation speed information f1, and the output of the acceleration sensor 91.

The generation unit 14 may generate a sound signal c1 corresponding to the output of the acceleration sensor 91 by using information indicating the correspondence between the output of the acceleration sensor 91 and the sound signal c1.

According to the fifth modification, the sound image control unit 15 can change the position of the sound image based on the output of the acceleration sensor 91.

B6: Sixth Modification In the first embodiment and the first to fifth modifications, the vehicle 100 may have an acceleration sensor 92 that detects acceleration of the vehicle 100 in the left-right direction.

FIG. 17 is a diagram showing an example of a vehicle 100 that further includes an acceleration sensor 92. The acceleration sensor 92 detects rightward acceleration when the vehicle 100 turns right. The acceleration sensor 92 detects leftward acceleration when the vehicle 100 turns left. The acquisition unit 13 may acquire the output of the acceleration sensor 92, i.e., information indicating the acceleration in the left-right direction of the vehicle 100. The sound image control unit 15 may use the output of the acceleration sensor 92 acquired by the acquisition unit 13 to determine the acceleration in the left-right direction of the vehicle 100.

The sound image control unit 15 may move the sound image localization of the sound output from the speakers 5a and 5b in the left-right direction of the vehicle 100 based on the output of the acceleration sensor 92. The sound image control unit 15 moves the sound image localization of the sound output from the speakers 5a and 5b in the left-right direction of the vehicle 100, for example, by executing a sound image localization process.

For example, the greater the acceleration to the right, the closer the sound image localization of the sound output from the speakers 5a and 5b to the right end 100R of the vehicle 100. The greater the acceleration to the left, the closer the sound image localization of the sound output from the speakers 5a and 5b to the left end 100L of the vehicle 100.

When the vehicle 100 accelerates to the right, the passenger receives a force directed to the left of the vehicle 100. Therefore, when the vehicle 100 accelerates to the right, the passenger feels the sound image moving to the right of the vehicle 100 in a state in which the passenger receives a force directed to the left of the vehicle 100. Therefore, compared to a case in which the sound image does not move, the passenger is more likely to feel the sensation of being pushed to the left of the vehicle 100 as the vehicle 100 accelerates to the right. Therefore, the passenger can feel immersed in the driving.

When the vehicle 100 accelerates to the left, the passenger receives a force directed to the right of the vehicle 100. Therefore, when the vehicle 100 accelerates to the left, the passenger feels the sound image moving to the left of the vehicle 100 in a state in which the passenger receives a force directed to the right of the vehicle 100. Therefore, compared to a case in which the sound image does not move, the passenger is more likely to feel the sensation of being pushed to the right of the vehicle 100 as the vehicle 100 accelerates to the left. Therefore, the passenger can feel immersed in the driving.

The sound image control unit 15 may move the sound image localization of the sound output from the speakers 5a and 5b closer to the left end 100L of the vehicle 100 as the acceleration in the right direction increases. In this case, the sound image control unit 15 moves the sound image localization of the sound output from the speakers 5a and 5b closer to the right end 100R of the vehicle 100 as the acceleration in the left direction increases.

In this configuration, when the vehicle 100 accelerates to the right, the passenger feels the sound image moving to the left of the vehicle 100 in a state where the vehicle 100 is subjected to a force moving to the left. Therefore, compared to a case where the sound image does not move, the passenger may be more likely to feel as if he or she is moving to the left of the vehicle 100 together with the sound image as the vehicle 100 accelerates to the right. This allows the passenger to feel immersed in the driving.

In addition, when the vehicle 100 accelerates to the left, the passenger feels the sound image moving to the right of the vehicle 100 when the vehicle 100 is subjected to a force moving to the right. Therefore, compared to when the sound image does not move, the passenger may be more likely to feel as if he or she is moving to the right of the vehicle 100 together with the sound image as the vehicle 100 accelerates to the left. This allows the passenger to feel immersed in the ride.

In the sixth variant, the sound image control unit 15 omits the process of shifting the sound image position of the sound output from the speakers 5a and 5b in the forward and backward directions.

In the sixth variant, if the process of moving the sound image localization of the sound output from the speakers 5a and 5b in the fore-and-aft direction of the vehicle 100 is not omitted, the sound image control unit 15 moves the sound image localization in the fore-and-aft direction, for example, by executing sound image localization process.

In the sixth modified example, the generation unit 14 may generate a sound signal c1 corresponding to the output of the acceleration sensor 92 by using information indicating the correspondence between the output of the acceleration sensor 92 and the sound signal c1.

B7: Seventh Modification In the sixth modification, the sound image control unit 15 may control the sound pressure of the sound output by the speaker 5a and the sound pressure of the sound output by the speaker 5b based on the output of the acceleration sensor 92, thereby shifting the sound image position of the sound output by the speakers 5a and 5b in the left-right direction. In this case, the speaker 5b is disposed to the left of the speaker 5a. For example, the speaker 5a may be disposed in the front right door 7b, and the speaker 5b may be disposed in the front left door 7a. The speaker 5a may be disposed in the rear right door 7d, and the speaker 5b may be disposed in the rear left door 7c.

When the position of the sound image is moved to the right, the sound image control unit 15 increases the sound pressure of the sound output by the speaker 5a and decreases the sound pressure of the sound output by the speaker 5b. When the position of the sound image is moved to the left, the sound image control unit 15 decreases the sound pressure of the sound output by the speaker 5a and increases the sound pressure of the sound output by the speaker 5b. The sound image control unit 15 changes both the sound pressure of the sound output by the speaker 5a and the sound pressure of the sound output by the speaker 5b by controlling both the amplitude of the sound signal c2a and the amplitude of the sound signal c2b.

According to the seventh modified example, the sound image control unit 15 can move the sound image localization of the sound output from the speakers 5a and 5b in the left-right direction without performing sound image localization processing to move the sound image localization in the left-right direction. In the seventh modified example, the sound image control unit 15 omits processing to move the sound image localization of the sound output from the speakers 5a and 5b in the front-back direction.

B8: Eighth Modification In the first embodiment and the first to seventh modifications, the sound image control unit 15 may include the generation unit 14. In this case, the sound image control unit 15 may generate the sound signal c1 based on vehicle information (for example, speed information a1, acceleration information, the output of the acceleration sensor 91, or the output of the acceleration sensor 92). For example, the sound data M1 to M25 shown in FIG. 7 are associated in advance with accelerations that may be specified in the vehicle information, and the sound image control unit 15 generates the sound signal c1 based on the sound data M corresponding to the accelerations specified in the vehicle information. The sound data M1 to M25 may indicate a waveform, a pitch, and a level of the sound. The sound data M1 to M25 are different from each other in at least one of the waveform shape, the pitch, and the level.

In addition, the sound image control unit 15 may control the sound image localization indirectly from the vehicle information, rather than directly from the vehicle information. For example, the sound image control unit 15 may move the sound image localization in the forward/backward direction of the vehicle 100 or the left/right direction of the vehicle 100 based on the characteristics of the sound (e.g., pitch or level) indicated by the sound signal c1 generated by the sound image control unit 15.

As an example, the greater the pitch of the sound indicated by the sound signal c1, the closer the sound image localization is to the first position i1 by the sound image control unit 15. The smaller the pitch of the sound indicated by the sound signal c1, the closer the sound image localization is to the second position i2 by the sound image control unit 15. The greater the pitch of the sound indicated by the sound signal c1, the closer the sound image localization may be to the second position i2 by the sound image control unit 15. In this case, the smaller the pitch of the sound indicated by the sound signal c1, the closer the sound image localization is to the first position i1 by the sound image control unit 15.

The sound image control unit 15 may bring the sound image localization closer to the first position i1 as the sound level indicated by the sound signal c1 is higher. In this case, the sound image control unit 15 brings the sound image localization closer to the second position i2 as the sound level indicated by the sound signal c1 is lower. The sound image control unit 15 may bring the sound image localization closer to the second position i2 as the sound level indicated by the sound signal c1 is higher. In this case, the sound image control unit 15 brings the sound image localization closer to the first position i1 as the sound level indicated by the sound signal c1 is lower.

The sound image control unit 15 may move the sound image closer to the right end 100R instead of moving the sound image closer to the first position i1. In this case, the sound image control unit 15 moves the sound image closer to the left end 100L instead of moving the sound image closer to the second position i2.

Instead of moving the sound image localization closer to the first position i1, the sound image control unit 15 may move the sound image localization closer to the left end 100L. In this case, instead of moving the sound image localization closer to the second position i2, the sound image control unit 15 moves the sound image localization closer to the right end 100R.

According to the eighth modified example, the sound image control unit 15 moves the sound image localization in the longitudinal direction or the lateral direction of the vehicle 100 based on the characteristics (pitch or level) of the sound indicated by the sound signal c1 (the sound output from the speakers 5a and 5b). This allows the passenger to feel immersed in the ride and to sense that the sound image localization is changing in response to changes in the characteristics of the sound output from the speakers 5a and 5b.

B9: Ninth Modification In the first embodiment and the first to eighth modifications, the sound indicated by the sound signal c1 is not limited to a virtual engine sound, and may be, for example, an animal cry or a piece of music having a tempo equal to or greater than a reference tempo. The reference tempo is, for example, a tempo equal to or greater than the average human heart rate. A piece of music having a tempo equal to or greater than the reference tempo is another example of a sound corresponding to the acceleration of a vehicle. In the first embodiment and the first to eighth modifications, the vehicle 100 is not limited to an electric vehicle, and may be a vehicle that runs using an engine as a power source. The virtual engine sound indicated by the sound signal c1 when the vehicle 100 is accelerating is an example of a sound corresponding to the acceleration of the vehicle.

C: Aspects Obtained from the Above-described Forms and Modifications The following aspects can be obtained from at least one of the above-described forms and modifications.

C1: First Aspect A sound image control device according to a first aspect of the present disclosure includes an acquisition unit that acquires vehicle information related to acceleration in the fore-and-aft direction of the vehicle, and a sound image control unit that shifts the sound image positioning of sound output from at least two speakers provided in the vehicle in the fore-and-aft direction of the vehicle based on the vehicle information acquired by the acquisition unit.

According to this embodiment, it is possible to move the sound image localization in the longitudinal direction of the vehicle in conjunction with the acceleration of the vehicle in the longitudinal direction. The passenger is more likely to recognize the acceleration of the vehicle in the longitudinal direction than in a case where the movement of the sound image localization is not recognized. Therefore, the passenger can feel immersed in the driving.

C2: Second Aspect In the example of the first aspect (second aspect), the at least two speakers include a first speaker and a second speaker located behind the first speaker, and the sound image control unit controls the sound pressure of the sound output from the first speaker and the sound pressure of the sound output from the second speaker based on the vehicle information to move the sound image localization in the front-rear direction of the vehicle. According to this aspect, for example, the sound image localization can be moved in the front-rear direction of the vehicle without using a sound transfer function.

C3: Third Aspect In the example of the second aspect (third aspect), the sound image control unit changes the magnitude relationship between the sound pressure of the sound output by the first speaker and the sound pressure of the sound output by the second speaker, thereby moving the sound image localization in the front-rear direction of the vehicle. According to this aspect, it is possible to increase the amount of movement of the sound image localization in the front-rear direction of the vehicle compared to a configuration in which the magnitude relationship between the sound pressure of the sound output by the first speaker and the sound pressure of the sound output by the second speaker is not changed.

C4: Fourth Aspect In any of the examples (fourth aspect) of the first to third aspects, the sound image control unit sets the sound image localization when the vehicle information indicates forward acceleration of the vehicle to a position that is moved forward of the vehicle compared to the sound image localization when the vehicle information does not indicate forward acceleration of the vehicle. According to this aspect, when the vehicle accelerates forward, the sound image localization moves forward. Therefore, when the vehicle accelerates forward, the passenger feels that the sound image moves forward of the vehicle in a state in which the vehicle receives a force toward the rear of the vehicle. Therefore, compared to when the sound image does not move, the passenger is more likely to feel that he or she is being pushed toward the rear of the vehicle as the vehicle accelerates forward. Therefore, the passenger can feel immersed in the driving.

C5: Fifth Aspect In any one of the first to fourth aspects (fifth aspect), the sound output from the at least two speakers is a sound corresponding to the acceleration of the vehicle. According to this aspect, when the vehicle accelerates, the passenger can get a sensation that the sound image localization of the sound corresponding to the acceleration of the vehicle moves in the front-rear direction.

C6: Sixth Aspect In any one of the examples (sixth aspect) of the first to fifth aspects, the sound output from the at least two speakers is generated based on the vehicle information, and the sound image control unit moves the sound image localization in the front-rear direction of the vehicle based on the pitch or level of the sound output from the at least two speakers. According to this aspect, the passenger can feel immersed in the driving, and can also feel the sound image localization changing in response to the change in the pitch or level of the sound output from the speakers.

C7: Seventh Aspect A sound image control device according to a seventh aspect of the present disclosure includes an acquisition unit that acquires vehicle information related to acceleration in the left-right direction of the vehicle, and a sound image control unit that shifts the sound image positioning of sound output from at least two speakers provided in the vehicle in the left-right direction of the vehicle based on the vehicle information acquired by the acquisition unit.

According to this embodiment, it is possible to move the sound image localization in the left-right direction of the vehicle in conjunction with the acceleration in the left-right direction of the vehicle. The passenger is more likely to recognize the acceleration in the left-right direction of the vehicle than in a case where the movement of the sound image localization is not recognized. Therefore, the passenger can feel immersed in the driving.

C8: Eighth Aspect In an example of the seventh aspect (eighth aspect), the at least two speakers include a first speaker and a second speaker located to the left of the first speaker, and the sound image control unit controls a sound pressure of a sound output from the first speaker and a sound pressure of a sound output from the second speaker based on the vehicle information to move the sound image localization in the left-right direction of the vehicle. According to this aspect, for example, the sound image localization can be moved in the left-right direction of the vehicle without using a transfer function of the sound.

In the example of the seventh or eighth aspect (ninth aspect), the sound output from the at least two speakers corresponds to the acceleration of the vehicle. According to this aspect, the passenger can get a sensation that the sound image position of the sound corresponding to the acceleration of the vehicle moves in the left and right direction when the vehicle accelerates.

C10: Tenth Aspect In any one of the seventh to ninth aspects (tenth aspect), the sound output from the at least two speakers is generated based on the vehicle information, and the sound image control unit moves the sound image localization in the left-right direction of the vehicle based on the pitch or level of the sound output from the at least two speakers. According to this aspect, the passenger can feel immersed in the driving and can feel the sound image localization changing in response to the change in the pitch or level of the sound output from the speakers.

C11: Eleventh Aspect A sound image control method according to an aspect (eleventh aspect) of the present disclosure is a sound image control method realized by a computer, which acquires vehicle information related to acceleration in a longitudinal direction of the vehicle, and moves a sound image position of the sound output from the at least two speakers in the longitudinal direction of the vehicle based on the acquired vehicle information.

According to this embodiment, it is possible to move the sound image localization in the longitudinal direction of the vehicle in conjunction with the acceleration of the vehicle in the longitudinal direction. The passenger is more likely to recognize the acceleration of the vehicle in the longitudinal direction than in a case where the movement of the sound image localization is not recognized. Therefore, the passenger can feel immersed in the driving.

C12: Twelfth Aspect A sound image control method according to a twelfth aspect of the present disclosure is a sound image control method implemented by a computer, which acquires vehicle information related to acceleration in the left-right direction of the vehicle, and shifts a sound image position of sound output from at least two speakers equipped in the vehicle in the left-right direction of the vehicle based on the acquired vehicle information.

According to this embodiment, it is possible to move the sound image localization in the left-right direction of the vehicle in conjunction with the acceleration in the left-right direction of the vehicle. The passenger is more likely to recognize the acceleration in the left-right direction of the vehicle than in a case where the movement of the sound image localization is not recognized. Therefore, the passenger can feel immersed in the driving.

1...sound image control device, 3...wheel control unit, 4...operation unit, 5a...speaker, 5b...speaker, 11...storage device, 12...processing device, 13...acquisition unit, 14...generation unit, 15...sound image control unit, 31...motor, 32...accelerator pedal, 33...shift lever, 34...motor control unit, 35...power transmission unit.

Claims (8)

An acquisition unit that acquires vehicle information related to acceleration in a forward/rearward direction of the vehicle;
a generator that generates a sound signal indicative of a sound corresponding to acceleration of the vehicle based on sound information stored in a storage device and the vehicle information;
a sound image control unit that shifts a sound image position of the sound output from at least two speakers provided in the vehicle in a front-rear direction of the vehicle based on the vehicle information;
Including,
the sound output from the at least two speakers corresponds to the acceleration of the vehicle as indicated by the sound signal ;
the sounds output from the at least two speakers are sounds generated based on the vehicle information,
the sound image control unit moves the sound image localization in a front-rear direction of the vehicle based on the levels of the sounds output from the at least two speakers.
Sound image control device. The at least two speakers include a first speaker and a second speaker located rearward of the first speaker,
The sound image control unit controls the sound pressure of the sound output from the first speaker and the sound pressure of the sound output from the second speaker based on the vehicle information, thereby moving the sound image localization in the front-rear direction of the vehicle.
The sound image control device according to claim 1 . The sound image control unit changes the magnitude relationship between the sound pressure of the sound output from the first speaker and the sound pressure of the sound output from the second speaker, thereby moving the sound image localization in the front-rear direction of the vehicle.
The sound image control device according to claim 2 . The sound image control unit sets the sound image localization when the vehicle information indicates forward acceleration of the vehicle to a position moved forward of the vehicle compared to the sound image localization when the vehicle information does not indicate forward acceleration of the vehicle.
The sound image control device according to any one of claims 1 to 3. An acquisition unit that acquires vehicle information related to acceleration in a left-right direction of the vehicle;
a generator that generates a sound signal indicative of a sound corresponding to acceleration of the vehicle based on sound information stored in a storage device and the vehicle information;
a sound image control unit that shifts a sound image position of the sound output from at least two speakers provided in the vehicle in a left-right direction of the vehicle based on the vehicle information;
Including,
the sound output from the at least two speakers corresponds to the acceleration of the vehicle as indicated by the sound signal ;
the sounds output from the at least two speakers are sounds generated based on the vehicle information,
the sound image control unit shifts the sound image localization in the left-right direction of the vehicle based on the levels of the sounds output from the at least two speakers.
Sound image control device. the at least two speakers include a first speaker and a second speaker located to the left of the first speaker;
The sound image control unit controls a sound pressure of the sound output from the first speaker and a sound pressure of the sound output from the second speaker based on the vehicle information, thereby moving the sound image localization in the left-right direction of the vehicle.
The sound image control device according to claim 5 . A computer-implemented sound image control method, comprising:
Acquire vehicle information relating to acceleration in a forward or rearward direction of the vehicle;
generating a sound signal indicative of a sound corresponding to acceleration of the vehicle based on the sound information stored in a storage device and the vehicle information;
Based on the vehicle information, a sound image position of the sound output from at least two speakers provided in the vehicle is moved in a forward/rearward direction of the vehicle;
the sound output from the at least two speakers corresponds to the acceleration of the vehicle as indicated by the sound signal ;
the sounds output from the at least two speakers are sounds generated based on the vehicle information,
shifting the sound image localization in the left-right direction of the vehicle based on the levels of the sounds output from the at least two speakers;
Sound image control method. A computer-implemented sound image control method, comprising:
Acquire vehicle information relating to acceleration in a lateral direction of the vehicle;
generating a sound signal indicative of a sound corresponding to acceleration of the vehicle based on the sound information stored in a storage device and the vehicle information;
Based on the vehicle information, a sound image position of the sound output from at least two speakers provided in the vehicle is shifted in a left-right direction of the vehicle;
the sound output from the at least two speakers corresponds to the acceleration of the vehicle as indicated by the sound signal ;
the sounds output from the at least two speakers are sounds generated based on the vehicle information,
the sound image control unit shifts the sound image localization in the left-right direction of the vehicle based on the levels of the sounds output from the at least two speakers.
Sound image control method.

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