Sound control method, sound control device, and electric vehicle

Abstract

To provide a sound control method, a sound control device, and an electric vehicle which, when a pseudo engine sound is output inside a vehicle capable of traveling with an electric motor, appropriately convey information according to an environmental situation of the vehicle to a driver while giving the driver a realistic sensation due to the output.SOLUTION: A method includes: S11 of acquiring information BEV such as a traveling state, a traveling environment, a surrounding environment, and a pseudo engine rotational rate of an electric vehicle; S12 of generating engine sound data EGS on the basis of the acquired information; S13 of estimating an environmental situation on the basis of the acquired information; S14 of determining whether processing conditions of an interior sound are satisfied on the basis of an estimation result of the environmental situation; S15 of outputting the engine sound data EGS to a speaker when a determination result is negative; and S16 of outputting post-processing sound data EGS_P obtained by processing the engine sound data EGS to the speaker when the determination result is positive.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a technique applied to an electric vehicle that uses an electric motor as a power device for running. [Background technology]

[0002] JP 2011-215437 A discloses a sound control device mounted on a vehicle that can run on an electric motor. This sound control device calculates the engine speed of a virtual engine based on vehicle travel information and simulation results of the operation of components of the virtual engine vehicle. This sound control device also controls virtual engine sound for the vehicle interior based on the calculated engine speed. In controlling this virtual engine sound, a sound effect corresponding to the operation of the components of the virtual engine vehicle is determined based on the simulation results of the operation of the components of the virtual engine vehicle. The determined sound effect is then added to the virtual engine sound.

[0003] In addition to JP 2011-215437 A, JP 2022-036005 A and JP 2011-213273 A can be exemplified as documents showing the technical state of the technical field related to the present disclosure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-215437 A [Patent Document 2] Patent Publication No. 2022-036005 [Patent Document 3] JP 2011-213273 A Summary of the Invention [Problem to be solved by the invention]

[0005] By adding sound effects corresponding to the operation of components of the virtual engine vehicle to the virtual engine sound, the driver of the vehicle is provided with a sense of realism as if he or she were driving a real engine vehicle. On the other hand, the driver of the vehicle is required to drive with consideration for the surroundings of the vehicle and to drive safely, and environmental situations in which the sense of realism should not be prioritized are also assumed. Therefore, from this perspective, there is room for improvement in the sound control device.

[0006] The present disclosure has been made in consideration of the above problems. One objective of the present disclosure is to provide a technology that, when outputting a pseudo engine sound into the cabin of a vehicle that can run on an electric motor, can appropriately convey information corresponding to the environmental conditions of the vehicle to the driver while giving the driver a sense of realism from the output. [Means for solving the problem]

[0007] A first aspect of the present disclosure is a sound control method applied to an electric vehicle that uses an electric motor as a power unit for traveling, and has the following features. The sound control method includes the steps of generating interior sound to be output from an interior speaker of the electric vehicle, estimating an environmental condition of the electric vehicle based on at least one of information related to the driving environment of the electric vehicle and information related to the surrounding environment of the electric vehicle, determining whether or not processing conditions for the interior sound are satisfied based on the estimated result of the environmental condition, and, if it is determined that the processing conditions for the interior sound are satisfied, processing the interior sound based on information on sound processing specifications corresponding to the estimated result of the environmental condition used in determining the processing conditions, and outputting the interior sound from the interior speaker.

[0008] A second aspect of the present disclosure is a sound control device that is applied to an electric vehicle that uses an electric motor as a power unit for traveling, and has the following features. The sound control device includes a storage device and a processor. The storage device stores information about the driving environment of the electric vehicle, information about the surrounding environment of the electric vehicle, and information indicating a correspondence between specific environmental conditions of the electric vehicle and sound processing specifications. The processor is configured to perform various processes. The processor is configured to generate indoor sound to be output from an indoor speaker of the electric vehicle, estimate an environmental condition of the electric vehicle based on at least one of information related to the driving environment of the electric vehicle and information related to the surrounding environment of the electric vehicle, determine whether or not the processing conditions for the indoor sound are satisfied based on the estimated result of the environmental condition, and if it is determined that the processing conditions for the indoor sound are satisfied, process the indoor sound based on information on sound processing specifications corresponding to the estimated result of the environmental condition used in determining the processing conditions, and output the indoor sound to the indoor speaker.

[0009] A third aspect of the present disclosure is an electric vehicle that uses an electric motor as a power unit for traveling, and has the following characteristics. The electric vehicle includes an indoor speaker, a storage device, and a processor. The storage device stores information about the driving environment of the electric vehicle, information about the surrounding environment of the electric vehicle, and information indicating a correspondence between specific environmental conditions of the electric vehicle and sound processing specifications. The processor is configured to perform various processes. The processor is configured to generate indoor sound to be output from the indoor speaker, estimate an environmental condition of the electric vehicle based on at least one of information related to the driving environment of the electric vehicle and information related to the surrounding environment of the electric vehicle, determine whether or not the processing conditions for the indoor sound are satisfied based on the estimated result of the environmental condition, and if it is determined that the processing conditions for the indoor sound are satisfied, process the indoor sound based on information on sound processing specifications corresponding to the estimated result of the environmental condition used in determining the processing conditions, and output the indoor sound to the indoor speaker. Effect of the Invention

[0010] According to the present disclosure, it is determined whether or not the processing conditions of the interior sound generated to be output from the interior speaker are satisfied based on the estimation result of the environmental condition of the electric vehicle. Then, when it is determined that the processing conditions are satisfied, the interior sound is processed based on the information of the sound processing specification corresponding to the estimation result used to determine the processing condition, and is output from the interior speaker. By processing the interior sound based on the information of the sound processing specification, it is possible to output the interior sound including information corresponding to the environmental condition of the vehicle from the interior speaker. Therefore, when the interior sound is output from the interior speaker, it is possible to appropriately convey information corresponding to the environmental condition of the electric vehicle to the driver. Also, when the interior sound includes a pseudo engine sound, it is possible to appropriately convey information corresponding to the environmental condition of the electric vehicle to the driver while giving the driver a sense of realism due to the output of the pseudo engine sound. [Brief description of the drawings]

[0011] [Figure 1] 1 is a conceptual diagram showing an electric vehicle and a sound control device according to a first embodiment. [Diagram 2] 1 is a block diagram showing an example of a basic functional configuration of a sound control device; [Diagram 3] 13 is a block diagram showing another example of the basic functional configuration of a sound control device. FIG. [Figure 4] 1 is a block diagram showing an example of a functional configuration of a sound control device that is particularly related to a first embodiment. [Diagram 5] 1 is a diagram illustrating an example of a relationship between a specific environmental situation and sound processing specifications. [Figure 6] FIG. 11 is a block diagram showing another example of the functional configuration of the sound control device that is particularly related to the first embodiment. [Figure 7] 4 is a flowchart showing the flow of sound control processing particularly related to the first embodiment. [Figure 8] FIG. 1 is a block diagram showing a first configuration example of a power control system for an electric vehicle. [Figure 9] 4A to 4C are diagrams showing examples of an engine model, a clutch model, and a transmission model that configure the MT vehicle model. [Figure 10] FIG. 11 is a diagram showing a comparison of the torque characteristics of an electric motor achieved by motor control using a MT vehicle model with the torque characteristics of an electric motor achieved by normal motor control in an electric vehicle. [Figure 11] FIG. 4 is a block diagram showing a second configuration example of a power control system for an electric vehicle. [Figure 12] FIG. 11 is a conceptual diagram showing the overall configuration of a system including a sound control device according to a second embodiment. [Figure 13] FIG. 11 is a block diagram showing an example of the functional configuration of a sound control device that is particularly related to a second embodiment. [Figure 14] FIG. 11 is a conceptual diagram showing an electric vehicle and a sound control device according to a third embodiment. [Figure 15] FIG. 13 is a block diagram showing an example of the functional configuration of a sound control device that is particularly related to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The embodiments of the present disclosure will be described with reference to the accompanying drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0013] 1. First embodiment 1-1. Overall configuration and simulated engine sound 1 is a conceptual diagram showing an electric vehicle 10 according to a first embodiment of the present disclosure and a sound control device 100 applied to the electric vehicle 10. The electric vehicle 10 is equipped with an electric motor 44. Examples of the electric motor 44 include a brushless DC motor and a three-phase AC synchronous motor. The electric vehicle 10 uses the electric motor 44 as a power unit for traveling.

[0014] The electric vehicle 10 is also equipped with various sensors 12. The various sensors 12 include operation state sensors such as an accelerator position sensor, a brake position sensor, and a shift position sensor, and driving state sensors such as a wheel speed sensor, an acceleration sensor, and a rotational speed sensor. The accelerator position sensor detects the amount of operation of the accelerator pedal (accelerator opening). The brake position sensor detects the amount of operation of the brake pedal. The shift position sensor detects the shift position. The wheel speed sensor detects the rotational speed of the wheels of the electric vehicle 10. The acceleration sensor detects the lateral acceleration and longitudinal acceleration of the electric vehicle 10. The rotational speed sensor detects the rotational speed of the electric motor 44.

[0015] The various sensors 12 also include position sensors such as a Global Navigation Satellite System (GNSS) sensor, recognition sensors such as a camera, radar, and Laser Imaging Detection and Ranging (LIDAR), sound sensors such as a microphone, and traffic visibility sensors such as a rain sensor, a fog sensor, and an illuminance sensor. The GNSS detects the position and attitude of the electric vehicle 10. The camera captures an image of at least the area in front of the electric vehicle 10. The radar and LIDAR recognize the situation around the electric vehicle 10. The microphone collects sounds around the electric vehicle 10. The rain sensor measures the amount of raindrops around the electric vehicle 10. The fog sensor measures the line of sight (visibility) ahead of the electric vehicle 10. The illuminance sensor measures the brightness around the electric vehicle 10.

[0016] The electric vehicle 10 also includes various switches 14. The various switches 14 include operational switches such as a turn signal switch, a light switch, a wiper switch, and an ignition switch. The turn signal switch switches the operating state (ON / OFF) of the direction indicator lights. The light switch switches the operating state (ON / OFF) of the lights (e.g., headlights, fog lights). The wiper switch switches the operating state (ON / OFF) of the wipers. The ignition switch switches the operating state (ON / OFF) of the vehicle's power supply circuit.

[0017] The electric vehicle 10 further includes a speaker 16. The speaker 16 corresponds to an "indoor speaker" in the present disclosure. The speaker 16 outputs sound to the interior of the electric vehicle 10. In the example shown in FIG. 1, the speaker 16 includes three front speakers 16a, 16b, and 16c and two rear speakers 16d and 16e. The total number of speakers constituting the speaker 16 and the layout of the speaker 16 can be changed as desired.

[0018] The sound control device 100 generates sound (hereinafter also referred to as "indoor sound") to be output from the speaker 16. The sound control device 100 also outputs the generated indoor sound from the speaker 16. For example, the sound control device 100 generates a pseudo engine sound as the indoor sound, and outputs the generated indoor sound from the speaker 16. In another example, the sound control device 100 generates indoor sound including a pseudo engine sound, and outputs the generated indoor sound from the speaker 16.

[0019] The entire sound control device 100 may be mounted on the electric vehicle 10. As another example, at least a part of the sound control device 100 may be included in a management server external to the electric vehicle 10. In that case, the sound control device 100 may generate indoor sounds remotely, receive the generated indoor sounds, and output them from the speaker 16.

[0020] Generally speaking, the sound control device 100 includes at least one processor 102 and at least one storage device 104. The processor 102 executes various processes. Examples of the processor 102 include a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), and a field-programmable gate array (FPGA). The storage device 104 stores (stores) various information. Examples of the storage device 104 include a volatile memory, a non-volatile memory, a hard disk drive (HDD), and a solid state drive (SSD).

[0021] 2 is a block diagram showing an example of the basic functional configuration of the sound control device 100. The sound control device 100 includes, as functional blocks, an information acquisition unit 110, a vehicle sound source management unit 120, an engine sound generation unit 130, and a sound output control unit 140. These functional blocks are realized, for example, by the cooperation of a processor 102 and a storage device 104.

[0022] The information acquisition unit 110 acquires information BEV about the electric vehicle 10. The information BEV includes information about the running state of the electric vehicle 10, information DEN about the running environment of the electric vehicle 10, information SEN about the surrounding environment of the electric vehicle 10, etc. The information BEV is typically detected, measured, etc. by various sensors 12 and various switches 14. A part of the information DEN is acquired by combining information detected by the various sensors 12 (e.g., position information) with three-dimensional map data.

[0023] The information BEV also includes a virtual engine rotation speed Ne. Here, it is assumed that the electric vehicle 10 uses a virtual engine as a power unit for traveling. The virtual engine rotation speed Ne is the rotation speed of the virtual engine when it is assumed that the electric vehicle 10 is driven by the virtual engine. For example, the information acquisition unit 110 may calculate the virtual engine rotation speed Ne so that it increases as the wheel speed increases. Furthermore, when the electric vehicle 10 has a manual mode (MT mode) described later, the information acquisition unit 110 may calculate the virtual engine rotation speed Ne in the manual mode based on the wheel speed, the overall reduction ratio, and the slip ratio of the virtual clutch. A method of calculating the virtual engine rotation speed Ne in the manual mode will be described later in detail.

[0024] The vehicle sound source management unit 120 stores sound source data EVS of the engine vehicle used to generate the pseudo engine sound. The vehicle sound source management unit 120 is mainly realized by the storage device 104. Typically, the sound source data EVS includes a plurality of types of sound source data. The plurality of types of sound source data includes, for example, sound source data (for low revolutions, medium revolutions, and high revolutions) of sounds caused by engine combustion, sound source data (for low revolutions, medium revolutions, and high revolutions) of sounds caused by the operation of input devices such as gears and clutches, sound source data of noise sounds, sound source data of event sounds (for example, engine stall sounds), and the like. Each sound source data is generated in advance through a simulation based on an engine model and a vehicle model of the engine vehicle. Each sound source data is flexibly adjustable. That is, at least one of the sound pressure and frequency of the sound indicated by the sound source data is flexibly adjustable.

[0025] The engine sound generation unit 130 (engine sound simulator) is a simulator that generates a pseudo engine sound. The engine sound generation unit 130 acquires at least a part of the information BEV from the information acquisition unit 110. In particular, the engine sound generation unit 130 acquires information on the virtual engine rotation speed Ne and the vehicle speed from the information acquisition unit 110. The engine sound generation unit 130 also reads the sound source data EVS of the engine vehicle from the vehicle sound source management unit 120. Then, the engine sound generation unit 130 generates a pseudo engine sound according to the driving state of the electric vehicle 10 (the virtual engine rotation speed Ne and the vehicle speed) by combining one or more sound source data included in the sound source data EVS of the engine vehicle. The engine sound data EGS is data indicating the generated pseudo engine sound.

[0026] Note that generating a pseudo engine sound is a well-known technique, and there is no particular limitation on the method of generating the pseudo engine sound that can be applied to the present disclosure. For example, the pseudo engine sound may be generated by a well-known engine sound simulator used in games, etc. A method may be used in which a map of virtual engine speed Ne vs. frequency and a map of virtual engine torque vs. sound pressure are prepared, and the frequency of the pseudo engine sound is increased or decreased in proportion to the virtual engine speed Ne, and the sound pressure of the pseudo engine sound is increased or decreased in proportion to the virtual engine torque.

[0027] The sound output control unit 140 receives the engine sound data EGS generated by the engine sound generation unit 130. Then, the sound output control unit 140 outputs the engine sound data EGS from the speaker 16. When outputting the engine sound data EGS, the sound output control unit 140 controls the sound pressure of the pseudo engine sound by controlling an amplifier. In addition, the sound output control unit 140 changes the frequency of the pseudo engine sound by controlling an FMC (frequency modulator).

[0028] FIG. 3 is a block diagram showing another example of the basic functional configuration of the sound control device 100. In the example shown in FIG. 3, the vehicle sound source management unit 120 stores sound source data EVS (EVS1, . . . EVSn) of multiple types of engine vehicles corresponding to multiple vehicle models (1, . . . , n). That is, the vehicle sound source management unit 120 stores sound source data EVS of engine vehicles for each vehicle model. The sound source data EVSk (1 ≦ k ≦ n) is generated in advance based on the engine model or vehicle model of the corresponding vehicle model. The driver may specify a vehicle model of his / her preference from among multiple vehicle models. In that case, the engine sound generation unit 130 acquires sound source data EVSk corresponding to the vehicle model specified by the driver. Then, the engine sound generation unit 130 generates a pseudo engine sound using the acquired sound source data EVSk of the engine vehicle. This allows the driver to get the feeling that he / she is driving a vehicle model of his / her preference.

[0029] 1-2. Processing of pseudo engine sounds The pseudo engine sound is output from the speaker 16, providing the driver of the electric vehicle 10 with a sense of realism as if he were driving a real engine vehicle. On the other hand, the driver is required to drive safely and with consideration for the surroundings of the electric vehicle 10. Therefore, in the first embodiment, the engine sound data EGS as the interior sound is appropriately processed based on the information included in the information BEV (specifically, at least one of the information DEN and the information SEN). Then, when this processing is performed, the processed engine sound data EGS (hereinafter also referred to as "engine sound data EGS_P") is output from the speaker 16.

[0030] Fig. 4 is a block diagram showing an example of a functional configuration of the sound control device 100 that is particularly related to the first embodiment. In the example shown in Fig. 4, the sound control device 100 includes an environmental situation estimation unit 150, a map management unit 160, a processing condition determination unit 170, and a sound effect management unit 180, in addition to the functional blocks described in Fig. 2. These functional blocks are realized, for example, by cooperation between the processor 102 and the storage device 104.

[0031] The environmental situation estimation unit 150 estimates the environmental situation of the electric vehicle 10 based on at least one of the information DEN and the information SEN. For example, the information SEN includes position information of the electric vehicle 10 acquired by a position sensor such as a GNSS sensor, recognition information of the surroundings of the electric vehicle 10 acquired by a recognition sensor such as a camera, environmental sound information of the surroundings of the electric vehicle 10 collected by a microphone, and traffic visibility information of the surroundings of the electric vehicle 10 acquired by a traffic visibility sensor such as a rain sensor. The information DEN includes driving area information of the electric vehicle 10, information on structures in the surroundings of the electric vehicle 10, and the like. The information DEN also includes operation information of operation switches such as a blinker switch. The information DEN may include vehicle type information of the engine vehicle specified by the driver.

[0032] The environmental condition estimation unit 150 also transmits the estimation result EES of the environmental condition of the electric vehicle 10 to the processing condition determination unit 170.

[0033] The map management unit 160 stores three-dimensional map data MAP. The map management unit 160 is mainly realized by the storage device 104. The three-dimensional map data MAP includes road position information, detailed road information (e.g., curves, types of straight lines, road curvature, longitudinal gradient, transverse gradient), intersection and branch point position information, and structure position information. The map management unit 160 combines the position information of the electric vehicle 10 with the three-dimensional map data MAP to generate information about the driving environment of the electric vehicle 10 (i.e., information DEN). The map management unit 160 transmits the generated information DEN to the environmental condition estimation unit 150.

[0034] The processing condition determination unit 170 determines whether or not the processing conditions of the engine sound data EGS as the interior sound are satisfied. The determination of whether or not the processing conditions are satisfied is performed based on the estimation result EES received from the environmental condition estimation unit 150. In the first embodiment, specific environmental conditions ES for processing the engine sound data EGS are listed in advance, and the list is referenced using the estimation result EES. Then, if there is an estimation result EES that matches the specific environmental condition ES, it is determined that the processing conditions are satisfied.

[0035] Specific environmental conditions ES are, for example: (1) Electric vehicles have poor visibility (2) The road surfaces on which electric vehicles run are poor. (3) Dynamic objects (e.g., pedestrians, bicycles) are detected around the electric vehicle. (4) The approach of emergency vehicles (e.g., ambulances, fire engines) to the electric vehicle is detected. (5) An electric vehicle is detected entering a noise-recommended area (e.g., a school zone, a railroad crossing zone, or a residential area). (6) When an electric vehicle changes lanes from the first lane to the second lane, a following vehicle is detected in the second lane. (7) The sound pressure of noise around electric vehicles (e.g., railroad crossing noise, pedestrian crossing noise, horn noise) exceeds a threshold. (8) Entry of an electric vehicle into a tunnel area is detected (9) Approach of electric vehicles to event areas (e.g., outdoor music festivals, fireworks, outdoor stadiums) is detected (10) An electric vehicle is detected entering a high altitude area. (11) The engine sound reproduction mode of an electric vehicle is set to the open-top car type reproduction mode.

[0036] The information DEN and / or information SEN used to estimate the environmental conditions corresponding to the specific environmental conditions ES(1)-(11) described above is, for example, as follows. (1) Raindrop measurement by rain sensor, visibility distance by fog sensor, and light switch operation status (2) Raindrop measurement by the rain sensor, recognition results based on camera images, and wiper switch operation status (3) Recognition results based on camera images (4) Analysis of surrounding environmental sounds by microphone and recognition results based on camera images (5) Current status of electric vehicles (6) Turn signal switch operation status, recognition result based on camera images (7) Analysis results of surrounding environmental sounds using microphones (8) Current status of electric vehicles (9) Current location of electric vehicle and analysis results of surrounding environmental sounds by microphone (10) Current location (altitude) of electric vehicle (11) The type of engine vehicle designated by the driver

[0037] When it is determined that the processing condition is satisfied, the processing condition determination unit 170 sets the sound processing specifications PS corresponding to the estimated result EES used in determining the processing condition. The set sound processing specifications PS are transmitted to the sound output control unit 140 and the sound effect management unit 180.

[0038] In the first embodiment, a correspondence relationship between specific environmental situations ES and sound processing specifications PS is set in advance. Fig. 5 is a diagram for explaining an example of the correspondence relationship between specific environmental situations ES and sound processing specifications PS. Fig. 5 shows specific environmental situations ES1, ES2, ES3, ES4, ..., ESi (i is a natural number) and sound processing specifications PS corresponding to each environmental situation ES. Specifically, the sound processing specification PS corresponding to environmental situation ES1 is PS1. In addition, the sound processing specification PS corresponding to environmental situation ES2 is PS2, the sound processing specification PS corresponding to environmental situation ES3 is PS3, the sound processing specification PS corresponding to environmental situation ES4 is PS1, and the sound processing specification PS corresponding to environmental situation ESi is PSj (j≦i).

[0039] The environmental situations ES1, ES2, ES3, ES4, ..., ESi are any of the specific environmental situations ES(1)-(11) described above. The sound processing specifications PS corresponding to the specific environmental situations ES(1)-(11) are, for example, as follows. (1) Reduce the sound pressure of the engine sound data EGS (including mute sound pressure. The same applies below.) (2) The output timing of the engine sound data EGS, which moves up and down in response to changes in the accelerator opening, is delayed from the normal output timing. (3) Reduce the sound pressure of the engine sound data EGS (4) Lowering the sound pressure of the engine sound data EGS, superimposing ambient sounds on the engine sound data EGS, or superimposing sound effects corresponding to emergency vehicle sounds on the engine sound data EGS. (5) Reduce the sound pressure of the engine sound data EGS (6) Reduce the sound pressure of the engine sound data EGS (7) Reduce the sound pressure of the engine sound data EGS (8) Superimposing sound effects corresponding to the tunnel wall reflections onto the engine sound data EGS (9) Lowering the sound pressure of the engine sound data EGS, superimposing ambient sounds on the engine sound data EGS, or superimposing sound effects corresponding to an event being held in the event area on the engine sound data EGS. (10) Superimposing sound effects corresponding to abnormal combustion sounds on the engine sound data EGS (11) Superimposing sound effects corresponding to the engine intake and exhaust sounds onto the engine sound data EGS

[0040] The sound effect management unit 180 stores sound source data EFS of sound effects. The sound effect management unit 180 is mainly realized by the storage device 104. The sound source data EFS includes a plurality of types of sound source data corresponding to a specific environmental situation ES. The plurality of types of sound source data includes, for example, sound source data of an emergency vehicle siren (emergency vehicle sound) corresponding to a specific environmental situation ES (4), sound source data of a sound (event sound) generated in an event corresponding to a specific environmental situation ES (8), sound source data of a tunnel reverberation sound corresponding to a specific environmental situation ES (9), sound source data of an abnormal combustion sound corresponding to a specific environmental situation ES (10), and sound source data of an engine intake sound and exhaust sound corresponding to a specific environmental situation ES (11). Each sound source data is generated in advance through a simulation or the like.

[0041] Based on the information on the sound processing specifications PS received from the processing condition determination section 170, the sound effect management section 180 transmits to the sound output control section 140 sound source data EFS of the sound effect corresponding to the sound processing specifications PS.

[0042] The sound output control unit 140 outputs the engine sound data EGS received from the engine sound generation unit 130 from the speaker 16. Up to this point, the functions are the same as those described in FIG. 2. When the sound processing specifications SP are received from the processing condition determination unit 170, the sound output control unit 140 processes the engine sound data EGS received from the engine sound generation unit 130 based on the information of the sound processing specifications SP. Then, the processed engine sound data EGS (i.e., engine sound data EGS_P) is output from the speaker 16. The sound pressure and output timing of the engine sound data EGS are changed, for example, by controlling the amplifier.

[0043] The sound effect is superimposed on the engine sound data EGS based on the sound source data EFS of the sound effect received from the sound effect management unit 180. Here, the sound processing specifications SP of the above-mentioned specific environmental situations (4) and (9) may include superimposing the sound effect only on the engine sound data EGS output from the speaker 16 in the estimated direction of the sound source (emergency vehicle, event venue). In this case, the engine sound data EGS_P may be output from the speaker 16 in the estimated direction of the sound source (for example, the front speaker 16b). In addition, the sound processing specifications SP of the specific environmental situation (8) may include adjusting the sound pressure of the reflected sound superimposed on the engine sound data EGS according to the difference in the lateral distance from the electric vehicle to the tunnel wall. For example, the sound pressure of the reflected sound of the speaker group close to the tunnel wall (for example, the front speaker 16b and the rear speaker 16d) may be relatively high, and that of the speaker group far from the tunnel wall (for example, the front speaker 16c and the rear speaker 16e) may be relatively low.

[0044] The surrounding environmental sound is superimposed on the engine sound data EGS using the environmental sound data ENS collected by the microphone. FIG. 6 is a block diagram showing an example of a functional configuration of the sound control device 100 for superimposing the surrounding environmental sound on the engine sound data EGS. In the example shown in FIG. 6, the sound control device 100 includes an environmental sound processing unit 190 instead of the sound effect management unit 180 described in FIG. 4. The environmental sound processing unit 190 temporarily stores the environmental sound data ENS of the surroundings of the electric vehicle 10 collected by the microphone included in the information SEN. When the sound processing specification PS is received from the processing condition determination unit 170, the environmental sound processing unit 190 transmits the environmental sound data ENS to the sound output control unit 140.

[0045] When the sound processing specification SP is received from the processing condition determination unit 170, the sound output control unit 140 processes the engine sound data EGS received from the engine sound generation unit 130 based on the information of the sound processing specification SP. The surrounding environmental sound is superimposed on the engine sound data EGS based on the environmental sound data ENS received from the environmental sound processing unit 190.

[0046] 1-3. Sound control processing Fig. 7 is a flowchart showing the flow of sound control processing particularly related to embodiment 1. The flowchart shown in Fig. 7 is repeatedly executed at a predetermined control period by the processor 102 shown in Fig. 1.

[0047] 7, first, information BEV is acquired (step S11). As described above, the information BEV is information about the electric vehicle 10, and includes information about the running state of the electric vehicle 10, information DEN about the running environment of the electric vehicle 10, information SEN about the surrounding environment of the electric vehicle, a virtual engine rotation speed Ne, etc.

[0048] Following the process of step S11, engine sound data EGS is generated (step S12). The engine sound data EGS is generated based on the information on the virtual engine rotation speed Ne and the vehicle speed acquired in step S11. When the information on the type of the engine vehicle specified by the driver is obtained in the process of step S11, the information on the type of the engine vehicle is combined with the information on the virtual engine rotation speed Ne and the vehicle speed to generate the engine sound data EGS.

[0049] Following the process of step S12, the environmental condition of the electric vehicle 10 is estimated (step S13). The environmental condition of the electric vehicle 10 is estimated based on at least one of the information DEN and the information SEN acquired in step S11. Once the environmental condition is estimated, an estimation result EES of the environmental condition is output.

[0050] Following the process of step S13, it is determined whether or not the processing conditions for the engine sound data EGS are satisfied (step S14). The determination of whether or not the processing conditions are satisfied is made based on whether or not there is an estimation result EES of the environmental situation output in step S13 that matches a specific environmental situation ES. If there is an estimation result EES that matches the specific environmental situation ES, it is determined that the processing conditions are satisfied.

[0051] If the determination result of step S14 is negative, engine sound data EGS is output to the speaker 16 (step S15). The engine sound data EGS output to the speaker 16 is generated in the processing of step S12. On the other hand, if the determination result of step S14 is positive, engine sound data EGS_P is output to the speaker 16 (step S16). The engine sound data EGS_P output to the speaker 16 is processed from the engine sound data EGS generated in the processing of step S12. The engine sound data EGS is processed based on sound processing specifications PS corresponding to the specific environmental situation ES that matches the estimated result EES in the determination of step S14.

[0052] 1-4.Effects According to the first embodiment, the engine sound data EGS is output from the speaker 16. Therefore, it is possible to provide the driver of the electric vehicle 10 with a sense of realism as if he or she were driving a real engine vehicle. Furthermore, when it is determined that the processing conditions for the engine sound data EGS are satisfied, the engine sound data EGS is processed based on the sound processing specifications PS, and the engine sound data EGS_P is output from the speaker 16. Therefore, an effect according to the sound processing specifications PS can be expected.

[0053] Examples of effects according to the sound processing specifications PS are as follows for the above-mentioned specific environmental situations ES(1)-(11). (1) By lowering the sound pressure of the engine sound data EGS when visibility is poor, the driver can be able to concentrate more easily with their eyes. (2) When the road surface is poor, the output timing of the engine sound data EGS is delayed more than usual, making the driver aware of the road surface conditions (slippery conditions). (3) When a moving object is present, the sound pressure of the engine sound data EGS can be reduced to alert the driver. (4) When an emergency vehicle is approaching, the sound pressure of the engine sound data EGS is reduced to make the driver aware of the approach. The driver can also be made aware of the approach of an emergency vehicle by superimposing the environmental sound data ENS or the sound source data EFS of the sound effect corresponding to the emergency vehicle sound on the engine sound data EGS. (5) By lowering the sound pressure of the engine sound data EGS when entering a noise-reduction recommended area, it becomes possible to drive an electric vehicle while being considerate of those around it (considerate driving). (6) By lowering the sound pressure of the engine sound data EGS when changing lanes from the first lane to the second lane, the increase in sound pressure is suppressed even if the electric vehicle accelerates during the lane change. Therefore, the driver can be made aware of the presence of a following vehicle in the second lane. (7) By lowering the sound pressure of the engine sound data EGS when ambient noise exceeds a threshold, the driver can be alerted to the surroundings of the electric vehicle. (8) When entering a tunnel area, the sense of realism can be enhanced by superimposing sound effects corresponding to tunnel reflections on the engine sound data EGS. (9) By lowering the sound pressure of the engine sound data EGS when approaching an event area, the driver can be made aware of the presence of the event. The driver can also be made aware of the presence of the event by superimposing the environmental sound data ENS or the sound source data EFS of the sound corresponding to the event being held in the event area on the engine sound data EGS. (10) When entering a high altitude area, the sense of realism can be enhanced by superimposing sound effects corresponding to the abnormal combustion sounds of the engine onto the engine sound data EGS. (11) When the open-top car reproduction mode is set, the sense of realism can be enhanced by superimposing sound effects corresponding to the intake sound and exhaust sound of the engine on the engine sound data EGS.

[0054] 1-5. Application to electric vehicles with manual mode (MT mode) The electric motor used as the power unit for driving a general electric vehicle has torque characteristics that are significantly different from those of the internal combustion engine used as the power unit for driving a conventional vehicle (CV). Due to the difference in torque characteristics of the power unit, a CV requires a transmission, whereas an electric vehicle generally does not have a transmission. Of course, a general electric vehicle does not have a manual transmission (MT) that allows the driver to manually change the gear ratio. For this reason, there is a significant difference in the driving sensation between driving a conventional vehicle with a MT (hereinafter also referred to as an "MT vehicle") and driving an electric vehicle.

[0055] On the other hand, the torque of an electric motor can be controlled relatively easily by controlling the applied voltage and the magnetic field. Therefore, with an electric motor, it is possible to obtain a desired torque characteristic within the operating range of the electric motor by implementing appropriate control. By utilizing this feature, the torque of an electric vehicle can be controlled to simulate the torque characteristic unique to a manual transmission vehicle. In addition, a pseudo shifter can be provided in the electric vehicle so that the driver can get the same driving sensation as in a manual transmission vehicle. This makes it possible to simulate a manual transmission vehicle in an electric vehicle.

[0056] That is, the electric vehicle controls the output of the electric motor so as to simulate the torque characteristics unique to a manual transmission vehicle. The driver operates the pseudo shifter to perform a pseudo manual gear shift operation. In response to the driver's pseudo manual gear shift operation, the electric vehicle changes the torque characteristics to simulate a manual transmission vehicle. This allows the driver of the electric vehicle to feel as if he or she is driving a manual transmission vehicle. The control mode of the electric motor for simulating the manual gear shift operation of a manual transmission vehicle in this way is hereinafter referred to as the "manual mode" or "MT mode."

[0057] The electric vehicle 10 according to the present disclosure may have such a manual mode (MT mode). In the MT mode, the electric vehicle 10 generates a pseudo engine sound according to the driving operation of the driver, and outputs the pseudo engine sound from the speaker 70. Since not only the driving operation of a MT vehicle but also the engine sound of a MT vehicle are reproduced, the satisfaction of drivers who seek realism is increased.

[0058] An example of the configuration of an electric vehicle 10 that has a manual mode (MT mode) will be described below.

[0059] 1-5-1. First configuration example 8 is a block diagram showing a first example of the configuration of a power control system of the electric vehicle 10. The electric vehicle 10 includes an electric motor 44, a battery 46, and an inverter 42. The electric motor 44 is a power device for driving the electric vehicle 10. The battery 46 stores electric energy for driving the electric motor 44. In other words, the electric vehicle 10 is a battery electric vehicle (BEV) that runs on electric energy stored in the battery 46. The inverter 42 converts DC power input from the battery 46 during acceleration into drive power for the electric motor 44. The inverter 42 also converts regenerative power input from the electric motor 44 during deceleration into DC power and charges the battery 46.

[0060] The electric vehicle 10 is provided with an accelerator pedal 22 that allows the driver to input an acceleration request to the electric vehicle 10. The accelerator pedal 22 is provided with an accelerator position sensor 32 that detects the accelerator opening degree.

[0061] The electric vehicle 10 is equipped with a pseudo shift paddle 24. This pseudo shift paddle 24 is a dummy that is different from an actual paddle-type shifter. The pseudo shift paddle 24 has a structure similar to a shift paddle equipped in a clutch pedal-less MT vehicle. The pseudo shift paddle 24 is attached to the steering wheel. The pseudo shift paddle 24 has an upshift switch and a downshift switch that determine the operation position. When the upshift switch is pulled toward the driver, it issues an upshift signal 34u, and when the downshift switch is pulled toward the driver, it issues a downshift signal 34d.

[0062] Wheel speed sensors 36 are provided on the wheels 26 of the electric vehicle 10. The wheel speed sensors 36 are used as vehicle speed sensors for detecting the speed of the electric vehicle 10. In addition, the electric motor 44 is provided with a rotation speed sensor 38 for detecting the rotation speed thereof.

[0063] The electric vehicle 10 includes a control device 50. The control device 50 is typically an electronic control unit (ECU) mounted on the electric vehicle 10. The control device 50 may be a combination of multiple ECUs. The control device 50 includes an interface, a memory, and a processor. An in-vehicle network is connected to the interface. The memory includes a RAM for temporarily recording data, and a ROM for storing programs executable by the processor and various data related to the programs. The programs are made up of multiple instructions. The processor reads the programs and data from the memory and executes them, and generates control signals based on signals acquired from each sensor.

[0064] For example, the control device 50 controls the electric motor 44 by PWM control of the inverter 42. Signals from the accelerator position sensor 32, the pseudo shift paddle 24, the wheel speed sensor 36, and the rotation speed sensor 38 (the signals from the pseudo shift paddle 24 are an upshift signal 34u and a downshift signal 34d) are input to the control device 50. The control device 50 processes these signals and calculates a motor torque command value for PWM controlling the inverter 42.

[0065] The control device 50 includes an automatic mode (EV mode) and a manual mode (MT mode) as control modes. The automatic mode is a normal control mode for driving the electric vehicle 10 as a general electric vehicle. The automatic mode is programmed to continuously change the output of the electric motor 44 in response to the operation of the accelerator pedal 22. On the other hand, the manual mode is a control mode for driving the electric vehicle 10 like a manual transmission vehicle. The manual mode is programmed to change the output characteristic of the electric motor 44 in response to the operation of the accelerator pedal 22 in response to an upshift operation and a downshift operation on the pseudo shift paddle 24. In other words, the manual mode is a control mode in which the output of the electric motor 44 can be changed in response to the driving operation of vehicle components other than the accelerator pedal 22 and the brake pedal. The automatic mode (EV mode) and the manual mode (MT mode) can be switched.

[0066] The control device 50 includes an automatic mode torque calculation unit 54 and a manual mode torque calculation unit 56. Each of the units 54 and 56 may be an independent ECU, or may be an ECU function obtained by executing a program recorded in a memory by a processor.

[0067] The automatic mode torque calculation unit 54 has a function of calculating the motor torque when the electric motor 44 is controlled in the automatic mode. A motor torque command map is stored in the automatic mode torque calculation unit 54. The motor torque command map is a map that determines the motor torque from the accelerator opening and the rotation speed of the electric motor 44. The signal of the accelerator position sensor 32 and the signal of the rotation speed sensor 38 are input to each parameter of the motor torque command map. The motor torque command map outputs a motor torque corresponding to these signals. Therefore, in the automatic mode, even if the driver operates the pseudo shift paddle 24, the operation is not reflected in the motor torque.

[0068] The manual mode torque calculation unit 56 includes an MT vehicle model. The MT vehicle model is a model for calculating the drive wheel torque that should be obtained by operating the accelerator pedal 22 and the pseudo shift paddles 24 when the electric vehicle 10 is assumed to be a MT vehicle.

[0069] The MT vehicle model provided in the manual mode torque calculation unit 56 will be described with reference to Fig. 9. As shown in Fig. 9, the MT vehicle model includes an engine model 561, a clutch model 562, and a transmission model 563. The engine, clutch, and transmission virtually realized by the MT vehicle model are referred to as a virtual engine, a virtual clutch, and a virtual transmission, respectively. The engine model 561 models a virtual engine. The clutch model 562 models a virtual clutch. The transmission model 563 models a virtual transmission.

[0070] The engine model 561 calculates a virtual engine rotation speed Ne and a virtual engine output torque Teout. The virtual engine rotation speed Ne is calculated based on the rotation speed Nw of the wheels, the total reduction ratio R, and the slip ratio Rslip of the virtual clutch. For example, the virtual engine rotation speed Ne is expressed by the following equation (1). Formula (1): Ne = Nw × R / (1 - Rslip)

[0071] The virtual engine output torque Teout is calculated from the virtual engine rotation speed Ne and the accelerator opening Pap. To calculate the virtual engine output torque Teout, a map is used that defines the relationship between the accelerator opening Pap, the virtual engine rotation speed Ne, and the virtual engine output torque Teout, as shown in FIG. 9. In this map, the virtual engine output torque Teout for the virtual engine rotation speed Ne is given for each accelerator opening Pap. The torque characteristics shown in FIG. 9 can be set to characteristics assuming a gasoline engine or to characteristics assuming a diesel engine. In addition, the torque characteristics can be set to characteristics assuming a naturally aspirated engine or to characteristics assuming a supercharged engine.

[0072] The clutch model 562 calculates a torque transmission gain k. The torque transmission gain k is a gain for calculating the degree of torque transmission of the virtual clutch according to the virtual clutch opening Pc. The virtual clutch opening Pc is usually 0%, and is temporarily opened to 100% in conjunction with the switching of the virtual gear stage of the virtual transmission. The clutch model 562 has a map as shown in FIG. 9. In this map, the torque transmission gain k is given for the virtual clutch opening Pc. In FIG. 9, Pc0 corresponds to the position where the virtual clutch opening Pc is 0%, and Pc3 corresponds to the position where the virtual clutch opening Pc is 100%. The ranges from Pc0 to Pc1 and from Pc2 to Pc3 are dead zones in which the torque transmission gain k does not change depending on the virtual clutch opening Pc. The clutch model 562 calculates the clutch output torque Tcout using the torque transmission gain k. The clutch output torque Tcout is the torque output from the virtual clutch. For example, the clutch output torque Tcout is given by the product of the virtual engine output torque Teout and the torque transmission gain k (Tcout=Teout×k).

[0073] Further, the clutch model 562 calculates a slip ratio Rslip. The slip ratio Rslip is used to calculate a virtual engine rotation speed Ne in the engine model 561. To calculate the slip ratio Rslip, a map in which the slip ratio Rslip is given with respect to the virtual clutch opening degree Pc can be used, similar to the torque transmission gain k.

[0074] The transmission model 563 calculates a gear ratio (speed ratio) r. The gear ratio r is a gear ratio determined by the virtual gear stage GP in the virtual transmission. In response to an upshift operation of the pseudo shift paddle 24, the virtual gear stage GP is increased by one stage. On the other hand, in response to a downshift operation of the pseudo shift paddle 24, the virtual gear stage GP is decreased by one stage. The transmission model 563 has a map as shown in FIG. 9. In this map, the gear ratio r is given to the virtual gear stage GP so that the gear ratio r becomes smaller as the virtual gear stage GP becomes larger. The transmission model 563 calculates the transmission output torque Tgout using the gear ratio r and the clutch output torque Tcout obtained from the map. For example, the transmission output torque Tgout is given as the product of the clutch output torque Tcout and the gear ratio r (Tgout=Tcout×r). The transmission output torque Tgout changes discontinuously in response to the switching of the gear ratio r. This discontinuous change in the transmission output torque Tgout generates a gear shift shock, creating the feeling that the vehicle is equipped with a stepped transmission.

[0075] The MT vehicle model calculates the driving wheel torque Tw using a predetermined reduction gear ratio rr. The reduction gear ratio rr is a fixed value determined by the mechanical structure from the virtual transmission to the driving wheels. The value obtained by multiplying the reduction gear ratio rr by the gear ratio r is the above-mentioned overall reduction gear ratio R. The MT vehicle model calculates the driving wheel torque Tw from the transmission output torque Tgout and the reduction gear ratio rr. For example, the driving wheel torque Tw is given by the product of the transmission output torque Tgout and the reduction gear ratio rr (Tw=Tgout×rr).

[0076] The control device 50 converts the driving wheel torque Tw calculated by the MT vehicle model into a required motor torque Tm. The required motor torque Tm is the motor torque required to realize the driving wheel torque Tw calculated by the MT vehicle model. The reduction ratio from the output shaft of the electric motor 44 to the driving wheels is used to convert the driving wheel torque Tw into the required motor torque Tm. Then, the control device 50 controls the inverter 42 according to the required motor torque Tm to control the electric motor 44.

[0077] Fig. 10 is a diagram showing a comparison of the torque characteristics of the electric motor 44 realized by motor control using the MT vehicle model with the torque characteristics of the electric motor 44 realized by normal motor control for an electric vehicle (EV). According to motor control using the MT vehicle model, as shown in Fig. 10, it is possible to realize torque characteristics (solid line in the figure) that simulate the torque characteristics of a MT vehicle according to the virtual gear stage set by the pseudo shift paddle 24. Note that in Fig. 10, the number of gear stages is set to six.

[0078] 1-5-2. Second configuration example 11 is a block diagram showing a second configuration example of the power control system of the electric vehicle 10. Here, only the configuration different from the first configuration example described above will be explained. Specifically, in the second configuration example, the electric vehicle 10 is provided with a pseudo shift lever 27 and a pseudo clutch pedal 28 instead of the pseudo shift paddle 24 provided in the first configuration example. The pseudo shift lever 27 and the pseudo clutch pedal 28 are merely dummies that are different from an actual shift lever and clutch pedal.

[0079] The pseudo shift lever 27 has a structure simulating a shift lever equipped in a manual transmission vehicle. The arrangement and operation feel of the pseudo shift lever 27 are the same as those of an actual manual transmission vehicle. The pseudo shift lever 27 has positions corresponding to each gear stage, for example, 1st, 2nd, 3rd, 4th, 5th, 6th, reverse, and neutral. The pseudo shift lever 27 is provided with a shift position sensor 27a that detects the gear stage by determining which position the pseudo shift lever 27 is in.

[0080] The pseudo clutch pedal 28 has a structure simulating a clutch pedal equipped in a manual transmission vehicle. The arrangement and operation feel of the pseudo clutch pedal 28 are the same as those of an actual manual transmission vehicle. The pseudo clutch pedal 28 is operated when the pseudo shift lever 27 is operated. That is, the driver depresses the pseudo clutch pedal 28 when he / she wishes to change the gear setting with the pseudo shift lever 27, and stops depressing the pseudo clutch pedal 28 when the gear setting change is completed and returns the pseudo clutch pedal 28 to its original position. The pseudo clutch pedal 28 is provided with a clutch position sensor 28a for detecting the amount of depression of the pseudo clutch pedal 28.

[0081] Signals are input to the control device 50 from the accelerator position sensor 32, the shift position sensor 27a, the clutch position sensor 28a, the wheel speed sensor 36, and the rotation speed sensor 38. The control device 50 processes these signals and calculates a motor torque command value for PWM controlling the inverter 42.

[0082] The control device 50 includes an automatic mode and a manual mode as control modes, similarly to the first configuration example described above. The automatic mode is programmed to continuously change the output of the electric motor 44 in response to the operation of the accelerator pedal 22. On the other hand, the manual mode is a control mode for driving the electric vehicle 10 like a manual transmission vehicle. The manual mode is programmed to change the output of the electric motor 44 in response to the operation of the accelerator pedal 22 in response to the operation of the pseudo clutch pedal 28 and the pseudo shift lever 27. In other words, the manual mode is a control mode in which the output of the electric motor 44 can be changed in response to the driving operation of vehicle components other than the accelerator pedal 22 or the brake pedal.

[0083] The vehicle model provided in the manual mode torque calculation unit 56 is similar to that shown in Fig. 9. However, the virtual clutch opening degree Pc is replaced with the depression amount of the pseudo clutch pedal 28 detected by the clutch position sensor 28a. Also, the virtual gear stage GP is determined by the position of the pseudo shift lever 27 detected by the shift position sensor 27a.

[0084] 2. Second embodiment 2-1. Overall structure Fig. 12 is a conceptual diagram showing the overall configuration of a system including a sound control device 100 according to a second embodiment of the present disclosure. In the example shown in Fig. 12, the sound control device 100 is connected to a navigation system 200 and an audio system 300. The basic configurations of the navigation system 200 and the audio system 300 are the same as that of the sound control device 100. That is, the navigation system 200 includes at least one processor 202 and at least one storage device 204. The audio system 300 includes at least one processor 302 and at least one storage device 304.

[0085] The navigation system 200 generates, for example, route guidance information from the current location of the electric vehicle 10 to a destination. The route guidance information includes guidance sounds. The navigation system 200 outputs the guidance sounds to the sound control device 100. The audio system 300 outputs audio sounds, such as the sounds of a radio and a television mounted on the electric vehicle 10 and music played on a music player of the electric vehicle 10, to the sound control device 100.

[0086] 2-2. Processing of pseudo engine sounds As in the first embodiment, in the second embodiment, engine sound data EGS is processed. Fig. 13 is a block diagram showing an example of the functional configuration of a sound control device 100 that is particularly related to the second embodiment. In the example shown in Fig. 13, the sound control device 100 includes functional blocks 100-170 excluding the sound effect management unit 180 shown in Fig. 4. These functional blocks are realized, for example, by cooperation between a processor 102 and a storage device 104.

[0087] The information acquisition unit 110 acquires operation information of the navigation system 200 and the audio system 300. The operation information is included in the information DEN relating to the traveling environment of the electric vehicle 10. The operation information of the navigation system 200 includes information on the output timing of the guidance sound data NVS.

[0088] The sound output control unit 140 receives engine sound data EGS generated by the engine sound generation unit 130. Up to this point, it is the same as the first embodiment. The sound output control unit 140 also receives guidance sound data NVS from the navigation system 200. The sound output control unit 140 further receives audio sound data ADS from the audio system 300. The sound output control unit 140 outputs the engine sound data EGS, the guidance sound data NVS, and the audio sound data ADS from the speaker 16.

[0089] The environmental condition estimation unit 150 estimates the environmental condition of the electric vehicle 10 based on the information DEN (specifically, information on the output timing of the guidance sound data NVS). The environmental condition estimation unit 150 also transmits the environmental condition estimation result EES to the processing condition determination unit 170.

[0090] The processing condition determination unit 170 determines whether the processing conditions for the interior sound including the engine sound data EGS, the guidance sound data NVS, and the audio sound data ADS are satisfied. The determination of whether the processing conditions are satisfied is performed based on the estimation result EES received from the environmental situation estimation unit 150. As in the first embodiment, in the second embodiment, a list is referenced using the estimation result EES. Then, if there is an estimation result EES that matches a specific environmental situation ES, it is determined that the processing conditions are satisfied.

[0091] In the second embodiment, the specific environmental situation ES is, for example, as follows. (12) The output timing for the guidance sound data NVS has arrived.

[0092] If it is determined that the processing condition is satisfied, the processing condition determination unit 170 sets the sound processing specifications PS corresponding to the estimation result EES used in determining this processing condition. The set sound processing specifications PS are transmitted to the sound output control unit 140. The sound processing specifications PS corresponding to a specific environmental situation ES(12) are, for example, as follows. (12) Lower the sound pressure of the engine sound data EGS while the guidance sound data NVS is being output, lower the sound pressure of the audio sound data ADS while the guidance sound data NVS is being output, or lower the sound pressure of the engine sound data EGS and the audio sound data ADS while the guidance sound data NVS is being output.

[0093] When the sound processing specifications SP are received from the processing condition determination unit 170, the sound output control unit 140 processes at least one of the engine sound data EGS received from the engine sound generation unit 130 and the audio sound data ADS received from the audio system 300, based on the information of the sound processing specifications SP. Then, the processed engine sound data EGS and audio sound data ADS, and the guidance sound data NVS are output from the speaker 16.

[0094] The flow of the sound control process related to the second embodiment is basically the same as that of the first embodiment described with reference to FIG.

[0095] 2-3.Effects According to the second embodiment, the same effects as those according to the first embodiment can be expected. An example of the effect according to the sound processing specifications PS will be described below with respect to the above-mentioned specific environmental situation ES (12). (12) By lowering the sound pressure of at least one of the engine sound data EGS and the audio sound data ADS, the guidance sound from the navigation system 200 can be properly conveyed to the driver.

[0096] 3. Third embodiment 3-1. Overall structure FIG. 14 is a conceptual diagram showing an electric vehicle 10 according to a third embodiment of the present disclosure and a sound control device 100 applied to the electric vehicle 10. In the example shown in FIG. 14, the electric vehicle 10 is equipped with a speaker 18. The speaker 18 corresponds to an "outdoor speaker" in the present disclosure. The speaker 18 outputs sound to the outside of the cabin of the electric vehicle 10. The total number of speakers constituting the speaker 18 and the layout of the speaker 18 can be changed as desired.

[0097] 3-2. Processing of pseudo engine sounds As in the first embodiment, in the third embodiment, engine sound data EGS is processed. Fig. 15 is a block diagram showing an example of the functional configuration of a sound control device 100 that is particularly related to the third embodiment. In the example shown in Fig. 15, the sound control device 100 includes an output condition determination unit 172 in addition to the functional blocks 100-160 shown in Fig. 4. These functional blocks are realized, for example, by cooperation between the processor 102 and the storage device 104.

[0098] The output condition determination unit 172 determines whether or not an output condition for the engine sound data EGS as the exterior sound is satisfied. The determination of whether or not the output condition is satisfied is made based on the estimation result EES received from the environmental condition estimation unit 150. As in the first embodiment, in the third embodiment, a list is referenced using the estimation result EES. Then, if there is an estimation result EES that matches a specific environmental condition ES, it is determined that the output condition is satisfied.

[0099] In the third embodiment, the specific environmental situation ES is, for example, as follows. (13) The speed of the electric vehicle is below a threshold. (14) No moving objects are detected around the electric vehicle, no approach of an emergency vehicle to the electric vehicle is detected, or no entry of the electric vehicle into a noise reduction recommended area is detected.

[0100] If it is determined that the output condition is satisfied, the output condition determination unit 172 transmits an output permission signal ENB of the exterior sound to the sound output control unit 140. If the output permission signal ENB is received, the sound output control unit 140 outputs the engine sound data EGS received from the engine sound generation unit 130 from the speaker 18. Here, the above-mentioned specific environmental situation (13) may include a situation in which the headlights of the electric vehicle 10 are not turned on. In other words, a situation in which the headlights are not turned on and the vehicle speed of the electric vehicle is equal to or lower than a threshold value may be determined as the specific environmental situation (13).

[0101] 3-3.Effects According to the third embodiment, when it is determined that the output condition is satisfied, the engine sound data EGS can be output outside the cabin of the electric vehicle 10. An example of the effect of outputting the engine sound data EGS outside the cabin will be described below with respect to the above-mentioned specific environmental situations ES (13) and (14). (13) When the speed of the electric vehicle is below a threshold, the engine sound data EGS is output to the outside of the vehicle, thereby making the electric vehicle's presence known to those around it. When the headlights are on, this effect can be achieved by a combination of the pseudo engine sound and light, or by light alone. (14) By limiting the environmental conditions in which engine sound data (EGS) is output outside the vehicle cabin, it becomes possible to drive an electric vehicle while taking into consideration its surroundings (considerate driving). [Explanation of symbols]

[0102] 10...electric vehicle, 12...various sensors, 14...various switches, 16, 18...speakers, 22...accelerator pedal, 24...pseudo shift paddle, 27...pseudo shift lever, 28...pseudo clutch pedal, 44...electric motor, 100...sound control device, 102, 202, 302...processor, 104, 204, 304...storage device, 110...information acquisition unit, 120...vehicle sound source management unit, 130...engine sound generation unit, 140...sound output control unit, 150...environmental situation estimation unit, 160...map management unit, 170...processing condition determination unit, 172...output condition determination unit, 180 ...sound effect management unit, 190...environmental sound processing unit, 200...navigation system, 300...audio system, ES...environmental situation, PS...sound processing specifications, ADS...audio sound data, BEV...information about electric vehicles, DEN...information about the driving environment of electric vehicles, EES...estimated result of environmental situation, EFS...sound effect source data, EGS...engine sound data, EGS_P...processed engine sound data, ENB...output permission signal, ENS...environmental sound data, EVS...sound source data of engine vehicle, SEN...information about the surrounding environment of electric vehicles

Claims

1. A sound control method applied to an electric vehicle that uses an electric motor as a power unit for driving, comprising: generating interior sounds for output through interior speakers of the electric vehicle; estimating an environmental condition of the electric vehicle based on at least one of information on a driving environment of the electric vehicle and information on a surrounding environment of the electric vehicle; determining whether or not the indoor sound processing condition is satisfied based on the result of the estimation of the environmental situation; When it is determined that the processing condition for the indoor sound is satisfied, processing the indoor sound based on information on a sound processing specification corresponding to the estimated result of the environmental situation used for determining the processing condition, and outputting the processed indoor sound from the indoor speaker; A sound control method comprising:

2. 2. The method of claim 1 , the indoor sound generated in the step of generating the indoor sound includes a pseudo engine sound generated based on operation information of a component of the electric vehicle, The components include an accelerator pedal, a simulated clutch pedal, and a simulated shift lever. A sound control method comprising:

3. 2. The method of claim 1 , the indoor sound generated in the step of generating the indoor sound includes a pseudo engine sound generated based on operation information of a component of the electric vehicle, The components include an accelerator pedal and a pseudo shift paddle. A sound control method comprising:

4. The method according to any one of claims 1 to 3, The interior sound processing conditions include that the visibility of the electric vehicle is poor; When the estimated result of the environmental condition is poor visibility of the electric vehicle, the sound processing specification includes processing for reducing the sound pressure of the interior sound. A sound control method comprising:

5. The method according to any one of claims 1 to 3, the indoor sound generated in the step of generating the indoor sound includes a pseudo engine sound generated based on operation information of a component of the electric vehicle, The components include an accelerator pedal; The interior sound processing condition includes that the road surface on which the electric vehicle is traveling is poor; When the estimated result of the environmental condition is that the road surface is poor, the sound processing specification includes processing for delaying the output timing of the pseudo engine sound from the indoor speaker, which is raised and lowered in response to a change in an accelerator opening, compared to the case where the estimated result of the environmental condition is not that the road surface is poor. A sound control method comprising:

6. The method according to any one of claims 1 to 3, The interior sound processing condition includes detecting a moving object around the electric vehicle; When the estimation result of the environmental condition is the detection of the dynamic object, the sound processing specification includes processing for lowering the sound pressure of the indoor sound. A sound control method comprising:

7. The method according to any one of claims 1 to 3, the interior sound processing condition includes detection of an approach of an emergency vehicle to the electric vehicle; When the estimation result of the environmental condition is the detection of the approach of the emergency vehicle, the sound processing specifications include processing to reduce the sound pressure of the interior sound, processing to superimpose a surrounding environmental sound of the electric vehicle on the interior sound, or processing to superimpose a sound effect corresponding to the emergency vehicle sound on the interior sound. A sound control method comprising:

8. The method according to any one of claims 1 to 3, The interior sound processing condition includes detecting that the electric vehicle enters a noise-recommended area; When the estimation result of the environmental condition is the detection of an entry into the quiet recommended area, the sound processing specification includes processing for lowering the sound pressure of the indoor sound. A sound control method comprising:

9. The method according to any one of claims 1 to 3, the processing condition for the interior sound includes detecting a following vehicle in the second lane when the electric vehicle is changing lanes from a first lane to a second lane; When the estimation result of the environmental condition is the detection of the following vehicle at the time of the lane change, the sound processing specification includes processing for lowering the sound pressure of the interior sound. A sound control method comprising:

10. The method according to any one of claims 1 to 3, The interior sound processing condition includes that the sound pressure of the ambient noise of the electric vehicle exceeds a threshold value; When the estimation result of the environmental condition indicates that the sound pressure of the ambient noise exceeds a threshold value, the sound processing specification includes processing for lowering the sound pressure of the indoor sound. A sound control method comprising:

11. The method according to any one of claims 1 to 3, the indoor sound generated in the step of generating the indoor sound includes a pseudo engine sound generated based on operation information of a component of the electric vehicle, The interior sound processing condition includes detecting that the electric vehicle enters a tunnel area; When the estimation result of the environmental condition is the detection of entry into the tunnel area, the sound processing specification includes processing for superimposing a sound effect corresponding to a tunnel wall reflection sound of the pseudo engine sound on the indoor sound. A sound control method comprising:

12. The method according to any one of claims 1 to 3, The interior sound processing condition includes detecting an approach of the electric vehicle to an event area; When the estimation result of the environmental condition is detection of approach to the event area, the sound processing specifications include processing to reduce the sound pressure of the indoor sound, processing to superimpose a surrounding environmental sound of the electric vehicle on the indoor sound, or processing to superimpose a sound effect corresponding to an event being held in the event area on the indoor sound. A sound control method comprising:

13. The method according to any one of claims 1 to 3, The interior sound processing condition includes detecting that the electric vehicle enters a high altitude area; When the estimated result of the environmental condition is the detection of an entry into the high altitude area, the sound processing specifications include processing for superimposing a sound effect corresponding to an abnormal combustion sound of a pseudo engine on the indoor sound. A sound control method comprising:

14. The method according to any one of claims 1 to 3, The interior sound processing conditions include that an engine sound reproduction mode of the electric vehicle is set to an open-top car type reproduction mode, When the estimated result of the environmental condition is the setting of the open-top car type playback mode, the sound processing specifications include processing for superimposing sound effects corresponding to the intake sound and exhaust sound of an engine on the interior sound. A sound control method comprising:

15. The method according to any one of claims 1 to 3, the indoor sound generated in the step of generating the indoor sound includes a pseudo engine sound generated based on operation information of components of the electric vehicle and a guidance sound by a navigation system mounted on the electric vehicle; the indoor sound processing condition includes that a timing for outputting the guidance sound has arrived, When the estimated result of the environmental condition indicates that the output timing of the guidance sound has arrived, the sound processing specification includes processing for lowering the sound pressure of the pseudo engine sound during output of the guidance sound. A sound control method comprising:

16. The method according to any one of claims 1 to 3, the indoor sound generated in the step of generating the indoor sound includes a pseudo engine sound generated based on operation information of components of the electric vehicle, a guidance sound by a navigation system mounted on the electric vehicle, and an audio sound by an audio system mounted on the electric vehicle; the indoor sound processing condition includes that a timing for outputting the guidance sound has arrived, When the estimation result of the environmental condition indicates that the output timing of the guidance sound has arrived, the sound processing specification includes processing for lowering a sound pressure of the audio sound during output of the guidance sound. A sound control method comprising:

17. The method according to any one of claims 1 to 3, generating exterior sound for output from an exterior speaker of the electric vehicle; determining whether or not an output condition for the outdoor sound is satisfied based on a result of the estimation of the environmental condition; outputting the outdoor sound from the outdoor speaker when it is determined that the output condition for the outdoor sound is satisfied; Further comprising: The exterior sound generated in the step of generating the exterior sound includes a pseudo engine sound generated based on operation information of components of the electric vehicle. A sound control method comprising:

18. 20. The method of claim 17, The output condition of the exterior sound includes that the vehicle speed of the electric vehicle is equal to or lower than a threshold value. A sound control method comprising:

19. 20. The method of claim 18, The output condition of the exterior sound includes that the headlights of the electric vehicle are not turned on. A sound control method comprising:

20. 20. The method of claim 17, The output condition of the exterior sound includes that a moving object is not detected around the electric vehicle, that an approach of an emergency vehicle to the electric vehicle is not detected, or that the electric vehicle is not detected entering a noise reduction recommended area. A sound control method comprising:

21. A sound control device applied to an electric vehicle that uses an electric motor as a driving power device, A storage device storing information on the driving environment of the electric vehicle, information on the surrounding environment of the electric vehicle, and information indicating a correspondence between a specific environmental condition of the electric vehicle and a sound processing specification; A processor configured to perform various processes; The processor, generating interior sounds for output from interior speakers of the electric vehicle; Estimating an environmental condition of the electric vehicle based on at least one of information on a driving environment of the electric vehicle and information on a surrounding environment of the electric vehicle; determining whether or not the indoor sound processing condition is satisfied based on the result of the estimation of the environmental condition; When it is determined that the processing condition for the indoor sound is satisfied, the indoor sound is processed based on information on a sound processing specification corresponding to the estimated result of the environmental situation used in determining the processing condition, and outputted to the indoor speaker. A sound control device characterized by being configured as follows.

22. An electric vehicle that uses an electric motor as a power unit for traveling, Indoor speakers and A storage device storing information on the driving environment of the electric vehicle, information on the surrounding environment of the electric vehicle, and information indicating a correspondence between a specific environmental condition of the electric vehicle and a sound processing specification; A processor that performs various processes based on the information stored in the storage device, The processor, generating indoor sounds for output from the indoor speakers; Estimating an environmental condition of the electric vehicle based on at least one of the information on the traveling environment and the information on the surrounding environment; determining whether or not the indoor sound processing condition is satisfied based on the result of the estimation of the environmental condition; When it is determined that the processing condition for the indoor sound is satisfied, the indoor sound is processed based on information on a sound processing specification corresponding to the estimated result of the environmental situation used in determining the processing condition, and outputted to the indoor speaker. An electric vehicle characterized by being configured as follows.

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