Sound control method, sound control device and electric car

Abstract

To make it possible that when pseudo engine sounds are outputted in a compartment of a vehicle which can be travelled by an electric motor, a sense of realism by this output is given to a driver.SOLUTION: Pseudo engine sounds are generated on the basis of operation information concerning a manual operation element of an electric car. The pseudo engine sounds are outputted from a plurality of speakers provided in a compartment of the electric car. The plurality of speakers include a first speaker provided on a front part of the electric car, and a second speaker provided at a place excluding the front part. When outputting pseudo engine sound from the plurality of speakers, each sound pressure of pseudo engine sounds outputted from the first and second speakers is adjusted on the basis of sound image setting information in the electric car.SELECTED DRAWING: Figure 9

Description

Technical Field

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

Background Art

[0002] Japanese Patent No. 6787507 discloses an electric vehicle that uses an electric motor as a driving power device. This conventional electric vehicle controls the output of the electric motor so as to simulate the torque characteristics peculiar to an engine vehicle with a manual transmission (hereinafter, also referred to as an "MT engine vehicle"). The control of the output of the electric motor is performed based on a signal from a pseudo-manual transmission operated by a driver. The pseudo-manual transmission has a configuration similar to that of the manual transmission mounted on an MT engine vehicle.

[0003] Japanese Unexamined Patent Application Publication No. 2020-120290 discloses a three-dimensional audio system for generating a three-dimensional sound field in a vehicle interior. This conventional audio system is a system retrofitted to an existing speaker system in the vehicle interior and includes speakers for three-dimensional audio. This conventional audio system outputs sound from the speakers for three-dimensional audio in conjunction with the existing speaker system.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Japanese Patent No. 6787507 does not mention the sound during the output control of the electric motor based on the driver's manual transmission operation. In this regard, if a sound (hereinafter also referred to as "pseudo engine sound") that simulates the engine sound of a general engine vehicle is output from a speaker provided in the interior of an electric vehicle, the driver can obtain a feeling of driving an engine vehicle. However, simply outputting the pseudo engine sound from the speaker may not be able to give a sufficient sense of presence to a driver who is accustomed to riding in an engine vehicle.

[0006] The present disclosure has been made in view of the above problems. One object of the present disclosure is to provide a technology capable of giving a driver a sense of presence by this output when outputting a pseudo engine sound in the interior of a vehicle that can be driven by an electric motor.

Means for Solving the Problems

[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 driving power device, and has the following features. The sound control method includes a step of generating a pseudo engine sound based on operation information of a manual driving element of the electric vehicle, and a step of outputting the pseudo engine sound from a plurality of speakers provided in the interior of the electric vehicle. The plurality of speakers include a first speaker provided at a front portion of the electric vehicle, and a second speaker provided at a location excluding the front portion. The step of outputting the pseudo engine sound further includes a step of adjusting each sound pressure of the pseudo engine sound output from the first and second speakers based on audio setting information in the electric vehicle.

[0008] A second aspect of the present disclosure is a sound control device applied to an electric vehicle that uses an electric motor as a driving power device, and has the following features. The sound control device includes a processor configured to perform various processes. The processor is configured to generate a pseudo engine sound based on operation information of manual driving elements of the electric vehicle and output the pseudo engine sound to a plurality of speakers provided in the interior of the electric vehicle. The plurality of speakers include a first speaker provided at a front portion of the electric vehicle and a second speaker provided at a location excluding the front portion. The processor is further configured to adjust each sound pressure of the pseudo engine sound output from the first and second speakers based on audio-visual setting information in the electric vehicle.

[0009] A third aspect of the present disclosure is an electric vehicle that uses an electric motor as a driving power device and has the following features. The electric vehicle includes a plurality of speakers provided in the interior of the electric vehicle and a processor configured to perform various processes. The processor is configured to generate a pseudo engine sound based on operation information of manual driving elements of the electric vehicle and output the pseudo engine sound to the plurality of speakers. The plurality of speakers include a first speaker provided at a front portion of the electric vehicle and a second speaker provided at a location excluding the front portion. The processor is further configured to adjust each sound pressure of the pseudo engine sound output from the first and second speakers based on audio-visual setting information in the electric vehicle.

Advantages of the Invention

[0010] According to the present disclosure, when a pseudo engine sound for output from first and second speakers provided in the interior of an electric vehicle is generated, each sound pressure of the pseudo engine sound output from these speakers is adjusted based on audio-visual setting information. Therefore, it is possible to enhance the sense of presence by this output as compared with the case where a pseudo engine sound is simply output from the first and second speakers.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Embodiments of the present disclosure will be described with reference to the accompanying drawings. In each figure, the same or corresponding components are denoted by the same reference numerals to simplify or omit the description.

[0013] 1. Overall Configuration and Pseudo Engine Sound FIG. 1 is a conceptual diagram showing an electric vehicle 10 according to an embodiment of the present disclosure and a sound control device 100 applied to the electric vehicle 10. The electric vehicle 10 includes 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 driving power device for traveling.

[0014] The electric vehicle 10 also includes 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 traveling state sensors such as a wheel speed sensor, an acceleration sensor, and a rotational speed sensor. The accelerator position sensor detects the operation amount (accelerator opening) of the accelerator pedal. The brake position sensor detects the operation amount 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 GNSS (Global Navigation Satellite System) sensor, and recognition sensors such as a camera, a radar, and a LIDAR (Laser Imaging Detection and Ranging). The GNSS detects the position and attitude of the electric vehicle 10. The camera images at least the front of the electric vehicle 10. The radar and the LIDAR recognize the surrounding situation of the electric vehicle 10.

[0016] The electric vehicle 10 also includes a first speaker 14 and a second speaker 16. The first speaker 14 and the second speaker 16 output sound inside the passenger compartment of the electric vehicle 10. FIG. 2 is a diagram showing an example layout of the first speaker 14 and the second speaker 16. In the example shown in FIG. 2, the first speaker 14 includes three front speakers 14a, 14b, and 14c. These front speakers are provided in the front part of the electric vehicle 10. The front speaker 14a is provided on the dashboard, for example. The front speaker 14b is provided on the left front door, for example. The front speaker 14c is provided on the right front door, for example. The front speakers 14a, 14b, and 14c may include speakers for different sound ranges such as a subwoofer, a midrange, and a tweeter. Note that the total number of speakers constituting the first speaker 14 and the layout of these speakers can be arbitrarily changed.

[0017] The second speaker 16 is a speaker provided at a location excluding the front part. In the example shown in FIG. 2, the second speaker 16 includes rear speakers 16a and 16b. These rear speakers are provided in the rear part of the electric vehicle 10. The rear speaker 16a is provided on the left rear door, for example. The rear speaker 16b is provided on the right rear door, for example. The second speaker 16 also includes seat speakers 16c, 16d, 16e, and 16f. The seat speakers 16c and 16d are provided on the headrest of the driver's seat, for example. The seat speakers 16e and 16f are provided on the headrest of the passenger seat, for example. The rear speakers 16a and 16b and the seat speakers 16c to 16f may include speakers for different sound ranges such as a subwoofer, a midrange, and a tweeter. Note that the total number of speakers constituting the second speaker 16 and the layout of these speakers can also be arbitrarily changed.

[0018] The electric vehicle 10 further includes an HMI (Human Machine Interface) unit 18. The HMI unit 18 is an input / output terminal for providing information to the driver of the electric vehicle 10 and receiving information from this driver. The HMI unit 18 includes, for example, an input device, a display device, and a microphone. Examples of the input device include a touch panel, a keyboard, a switch, and a button. The information provided to the driver includes information regarding the driving state of the electric vehicle 10 and information specific to this disclosure. The information specific to this disclosure includes information regarding the driving mode of the electric vehicle 10 and information regarding the audio-visual settings. The provision of information to the driver is performed using the display device. The reception of information from the driver is performed using the input device and the microphone.

[0019] The sound control device 100 generates sound (hereinafter also referred to as "interior sound") for output from the first speaker 14 and the second speaker 16. The sound control device 100 also outputs the generated interior sound from the first speaker 14 and the second speaker 16. For example, the sound control device 100 generates pseudo engine sound as the interior sound and outputs it from the first speaker 14 and the second speaker 16. In another example, the sound control device 100 generates interior sound including pseudo engine sound and outputs it from the first speaker 14 and the second speaker 16.

[0020] 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 outside the electric vehicle 10. In that case, the sound control device 100 may remotely generate interior sound, receive the generated interior sound, and output it from the first speaker 14 and the second speaker 16.

[0021] 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 CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), and the like. The storage device 104 stores (stores) various information. Examples of the storage device 104 include a volatile memory, a non-volatile memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), and the like.

[0022] Figure 3 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 the processor 102 and the storage device 104.

[0023] The information acquisition unit 110 acquires information BEV regarding the electric vehicle 10. The information BEV includes information regarding the driving state of the electric vehicle 10, information regarding the driving environment of the electric vehicle 10, input information from the driver of the electric vehicle 10, and the like. The information BEV is typically detected by various sensors 12 and the HMI unit 18. A part of the information regarding the driving environment of the electric vehicle 10 may be acquired by combining information detected by various sensors 12 (for example, the position information of the electric vehicle 10) with map data.

[0024] Also, the information BEV includes the virtual engine rotational speed Ne. Here, it is assumed that the electric vehicle 10 uses a virtual engine as a driving power device. The virtual engine rotational speed Ne is the rotational 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 rotational speed Ne so as to increase as the wheel speed increases. Further, when the electric vehicle 10 is provided with a manual mode described later, the information acquisition unit 110 may calculate the virtual engine rotational speed Ne in the manual mode based on the wheel speed, the overall reduction ratio, and the slip ratio of the virtual clutch. Details of the method for calculating the virtual engine rotational speed Ne in this manual mode will be described later.

[0025] The vehicle sound source management unit 120 stores the sound source data EVS of the engine vehicle used for generating a 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 multiple types of sound source data. The multiple types of sound source data include, for example, sound source data of sounds caused by engine combustion (for low rotational speeds, medium rotational speeds, high rotational speeds), sound source data of sounds caused by operations of input devices such as gears (for low rotational speeds, medium rotational speeds, high rotational speeds), sound source data of engine intake sounds, sound source data of engine exhaust sounds, sound source data of noise sounds, sound source data of event sounds (such as engine stall sounds), etc. Each sound source data is generated in advance through simulations based on the engine model and 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.

[0026] 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. Further, the engine sound generation unit 130 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 corresponding to the driving state (virtual engine rotation speed Ne and vehicle speed) of the electric vehicle 10 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.

[0027] Incidentally, the generation of the pseudo engine sound is a well-known technique, and the generation method of the pseudo engine sound applicable to the present disclosure is not particularly limited. For example, a pseudo engine sound may be generated by a well-known engine sound simulator employed in a game or the like. A map of virtual engine rotation speed Ne - frequency and a map of virtual engine torque - sound pressure may be provided, and a method of increasing or decreasing the frequency of the pseudo engine sound in proportion to the virtual engine rotation speed Ne and increasing or decreasing the sound pressure of the pseudo engine sound in proportion to the virtual engine torque may also be used.

[0028] 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 to 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. Further, the sound output control unit 140 changes the frequency of the pseudo engine sound by controlling an FMC (frequency modulator).

[0029] FIG. 4 is a block diagram showing another example of the basic functional configuration of the sound control device 100. In the example shown in FIG. 4, the vehicle sound source management unit 120 stores sound source data EVS (EVS1, ···, EVSn) of a plurality of types of engine vehicles corresponding to each of a plurality of vehicle types (1, ···, n). That is, the vehicle sound source management unit 120 stores the sound source data EVS of the engine vehicle for each vehicle type. The sound source data EVSk (1 ≤ k ≤ n) is generated in advance based on the engine model and vehicle model of the corresponding vehicle type. The driver may specify their preferred vehicle type from among the plurality of vehicle types. In that case, the engine sound generation unit 130 acquires the sound source data EVSk corresponding to the vehicle type 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. Thereby, the driver can obtain the feeling of driving their preferred vehicle type.

[0030] 2. Adjustment of the sound pressure of the pseudo engine sound By outputting the pseudo engine sound from the first speaker 14 and the second speaker 16, a sense of presence as if driving an actual engine vehicle is provided to the driver of the electric vehicle 10. However, simply outputting the pseudo engine sound from these speakers may not provide a sufficient sense of presence to a driver accustomed to an engine vehicle. Therefore, in the embodiment, the sound pressure of each of the pseudo engine sounds output from the first speaker 14 and the second speaker 16 is adjusted. By adjusting each sound pressure, it becomes easier for the driver to recognize the direction of the sound source. Therefore, it is possible to enhance the sense of presence compared to the case of simply outputting the pseudo engine sound from the first speaker 14 and the second speaker 16.

[0031] FIG. 5 is a block diagram showing an example of the functional configuration of the sound control device 100 particularly related to the embodiment. In the example shown in FIG. 5, the sound control device 100 includes a sound image setting unit 150 in addition to the functional blocks described in FIG. 3. These functional blocks are realized, for example, by the cooperation of the processor 102 and the storage device 104.

[0032] The audio - video setting unit 150 sets the audio - video in the interior of the electric vehicle 10 based on the information SPK. The information SPK is information regarding the settings of the first speaker 14 and the second speaker 16, and is an example of the "audio - video setting information" of the present disclosure. The information SPK is included, for example, in the input information from the driver acquired from the HMI unit 18.

[0033] FIG. 6 is a diagram for explaining information regarding the settings of the speakers. In the example shown in FIG. 6, the HMI unit 18 is configured by a touch panel. On this touch panel, a screen for setting the sound pressure of each of the first speaker 14 and the second speaker 16 is output. On the left side of this setting screen, the in - vehicle positions of each speaker are shown, and on the right side of the same setting screen, the sound - pressure bars of each speaker are shown. The button BT shown above the sound - pressure bar can slide in the left - right direction. When the button BT is slid to the right, the sound pressure increases, and when the button BT is slid to the left, the sound pressure decreases. Thus, in the example shown in FIG. 6, the sound pressure of each of the first speaker 14 and the second speaker 16 is set by the driver.

[0034] In another example, the information regarding the speaker settings is automatically generated based on the information on the mounting position of the engine in the vehicle type specified by the driver. FIG. 7 is a diagram for explaining the information SPK when the pseudo - engine sound is generated using the sound source data EVSk described in FIG. 4. When the vehicle type Ek is specified by the driver, based on the information on the mounting position (for example, front, rear, mid - ship) of the engine of this vehicle type Ek, the default settings of the sound pressure of each of the first speaker 14 and the second speaker 16 are output to the HMI unit 18 (touch panel).

[0035] FIG. 7 shows the default settings for vehicle type Ek when it is a midship engine vehicle. In a midship engine vehicle, since the engine is mounted in front of the rear wheel axle, in the default settings, the sound pressures of the rear speakers 16a and 16b around the mounting position of this engine and the seat speakers 16c to 16f are high. On the other hand, the sound pressures of the front speakers 14a to 14c, which are relatively far from the engine mounting position, are low (the lowest value in FIG. 7). The driver who specifies vehicle type Ek can adopt this default setting as it is. The driver can also adjust the default setting. For example, when there is no passenger in the passenger seat, the sound pressures of the seat speakers 16e and 16f can be lowered.

[0036] The information SPK may be obtained from an input / output terminal other than the HMI unit 18. FIG. 8 is a diagram for explaining an example of obtaining the information SPK from the user terminal 200. The user terminal 200 shown in FIG. 8 is a terminal (for example, a smartphone or a tablet) carried by the driver or a passenger of the electric vehicle 10. The user terminal 200 is configured to be communicable with the sound control device 100. By launching a predetermined application on the user terminal 200, a setting screen similar to the setting screen output to the HMI unit 18 is output to the display unit of the user terminal 200. When this setting screen is output to the display unit, the driver can set the speakers without going through the HMI unit 18. Also, the passenger of the electric vehicle 10 can change the setting of the sound image around the seat of this passenger to a setting according to their preference.

[0037] Figures 6 and 8 also show information regarding the settings of the engine intake sound and the engine exhaust sound below the setting screen. This information is used to set whether or not to superimpose the pseudo engine intake sound and the pseudo engine exhaust sound on the pseudo engine sound. When the superimposition setting of the engine intake sound is performed, a pseudo engine intake sound simulating the engine intake sound is superimposed on the pseudo engine sound output from the first speakers 14 (i.e., the front speakers 14a, 14b, and 14c). When the superimposition setting of the engine exhaust sound is performed, a pseudo engine exhaust sound simulating the engine exhaust sound is superimposed on the pseudo engine sound output from the rear speakers 16a and 16b. The superimposition of the pseudo engine exhaust sound may be performed on the pseudo engine sound output from the seat speakers 16c to 16f. Note that the superimposition process of the pseudo engine intake sound and the pseudo engine exhaust sound is performed in the engine sound generation unit 130.

[0038] When the audio setting unit 150 sets the audio in the interior of the electric vehicle 10, the audio setting unit 150 transmits the sound pressure adjustment information MDF of each speaker to the sound output control unit 140.

[0039] The sound output control unit 140 outputs the engine sound data EGS received from the engine sound generation unit 130 from the speakers 14. So far, this is the same function as described in FIG. 3. When the sound output control unit 140 receives the sound pressure adjustment information MDF from the audio setting unit 150, the sound output control unit 140 adjusts the sound pressure of the pseudo engine sound output from each speaker based on the sound pressure adjustment information MDF, and outputs the engine sound data EGS to the first speakers 14 and the second speakers 16. The adjustment of the sound pressure is performed, for example, by controlling each amplifier of the first speakers 14 and the second speakers 16.

[0040] 3. Sound control process FIG. 9 is a flowchart showing the flow of the sound control process particularly related to the embodiment. The flowchart shown in FIG. 9 is repeatedly executed by the processor 102 shown in FIG. 1 at a predetermined control cycle.

[0041] In the routine shown in FIG. 9, first, information BEV is acquired (step S11). As described above, it includes information regarding the driving state of the electric vehicle 10, information regarding the driving environment of the electric vehicle 10, input information from the driver of the electric vehicle 10, the virtual engine rotation speed Ne, and the like.

[0042] Following the process of step S11, engine sound data EGS is generated (step S12). The engine sound data EGS is generated based on the virtual engine rotation speed Ne and vehicle speed information obtained in the process of step S11. If information on the vehicle type of the engine vehicle specified by the driver is obtained in the process of step S11, the engine sound data EGS is generated by combining this vehicle type information with the virtual engine rotation speed Ne and vehicle speed information.

[0043] Following the process of step S12, sound pressure adjustment information MDF is generated (step S13). The sound pressure adjustment information MDF is generated based on the input information from the driver obtained in the process of step S11. The input information from the driver may be input via the HMI unit 18 or may also be input via the user terminal 200. When the passenger of the electric vehicle 10 carries the user terminal 200, the sound pressure adjustment information MDF is generated based on the input information from the driver and the input information from the passenger.

[0044] Following the process of step S13, the sound pressure of the pseudo engine sound output from each speaker is adjusted (step S14). The sound pressure adjustment is performed based on the sound pressure adjustment information MDF generated in the process of step S13. Following the process of step S14, the engine sound data EGS is output to the first speaker 14 and the second speaker 16 respectively (step S15).

[0045] 4. Effects According to the embodiment, engine sound data EGS is output from the first speaker 14 and the second speaker 16. Therefore, a sense of presence as if driving an actual engine vehicle can be provided to the driver of the electric vehicle 10. In addition, based on the sound pressure adjustment information MDF, the sound pressure of each of the pseudo engine sounds output from these speakers is adjusted. Therefore, it is possible to enhance the sense of presence due to this output as compared with the case where a pseudo engine sound is simply output from the first speaker 14 and the second speaker 16.

[0046] 5. Application to an electric vehicle equipped with a manual mode An electric motor used as a driving power device in a general electric vehicle has significantly different torque characteristics from an internal combustion engine that has been used as a driving power device in a conventional engine vehicle. Due to the difference in the torque characteristics of the power device, a transmission is essential for a conventional engine vehicle, while a general electric vehicle generally does not have a transmission. Also, a general electric vehicle does not have a manual transmission that is operated by a driver. For this reason, there is a significant difference in the driving feeling between driving an MT engine vehicle and driving an electric vehicle.

[0047] On the other hand, an electric motor can relatively easily control torque by controlling the applied voltage and field excitation. Therefore, in an electric motor, by implementing appropriate control, it is possible to obtain desired torque characteristics within the operating range of the electric motor. Taking advantage of this feature, the torque of an electric vehicle can be controlled to simulate the torque characteristics peculiar to an MT engine vehicle. Also, a pseudo manual transmission can be provided in the electric vehicle so that the driver can obtain a driving feeling like that of an MT engine vehicle. By these means, it becomes possible to simulate an MT engine vehicle in an electric vehicle.

[0048] In an embodiment, the output of the electric motor 44 may be controlled so as to simulate torque characteristics specific to an MT engine vehicle. By controlling the output of the electric motor 44, the driver of the electric vehicle 10 can obtain a feeling as if driving an MT engine vehicle. The control mode of the electric motor 44 for simulating the torque characteristics specific to an MT engine vehicle is hereinafter also referred to as the "manual mode". Further, the control mode of the electric motor 44 for driving the electric vehicle 10 as a general electric vehicle is hereinafter also referred to as the "automatic mode".

[0049] Hereinafter, a configuration example of the electric vehicle 10 having a manual mode will be described.

[0050] 5-1. First Configuration Example FIG. 10 is a block diagram showing a first configuration example of the 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 running. The battery 46 stores electric energy for driving the electric motor 44. That is, the electric vehicle 10 is a battery electric vehicle (BEV) that runs on the electric energy stored in the battery 46. The inverter 42 converts the DC power input from the battery 46 during acceleration into the driving power of the electric motor 44. Further, the inverter 42 converts the regenerative power input from the electric motor 44 during deceleration into DC power and charges the battery 46.

[0051] The electric vehicle 10 includes an accelerator pedal 22 for the driver to input an acceleration request for the electric vehicle 10. The accelerator pedal 22 is provided with an accelerator position sensor 32 for detecting the accelerator opening.

[0052] The electric vehicle 10 is equipped with a pseudo shift paddle 24. This pseudo shift paddle 24 is a dummy different from the original paddle-type shifter. The pseudo shift paddle 24 has a structure modeled after the shift paddle provided in a clutch pedal-less MT engine vehicle. The pseudo shift paddle 24 is attached to the steering wheel. The pseudo shift paddle 24 includes an upshift switch and a downshift switch that determine the operation position. The upshift switch issues an upshift signal 34u when pulled forward, and the downshift switch issues a downshift signal 34d when pulled forward.

[0053] A wheel speed sensor 36 is provided on the wheel 26 of the electric vehicle 10. The wheel speed sensor 36 is used as a vehicle speed sensor for detecting the vehicle speed of the electric vehicle 10. Also, a rotational speed sensor 38 for detecting the rotational speed is provided on the electric motor 44.

[0054] The electric vehicle 10 is equipped with 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 a plurality of 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 program is composed of a plurality of instructions. The processor reads the program and data from the memory and executes them, and generates a control signal based on the signals acquired from each sensor.

[0055] 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 rotational speed sensor 38 (the signal from the pseudo shift paddle 24 is the upshift signal 34u and the 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 control of the inverter 42.

[0056] The control device 50 includes an automatic mode and a manual 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 according 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 an MT engine vehicle. The manual mode is programmed to change the output characteristics of the electric motor 44 with respect to the operation of the accelerator pedal 22 according to the upshift operation and the downshift operation with respect to the pseudo shift paddle 24. That is, the manual mode is a control mode capable of changing the output of the electric motor 44 in response to the driving operation of manual driving elements other than the accelerator pedal 22 and the brake pedal. The automatic mode and the manual mode are switchable.

[0057] 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 a function of an ECU obtained by executing a program recorded in a memory by a processor.

[0058] The automatic mode torque calculation unit 54 has a function of calculating the motor torque when controlling the electric motor 44 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 rotational speed of the electric motor 44. Signals from the accelerator position sensor 32 and the rotational speed sensor 38 are input to each parameter of the motor torque command map. Motor torque corresponding to these signals is output from the motor torque command map. Therefore, in the automatic mode, even if the driver operates the pseudo shift paddle 24, the operation is not reflected in the motor torque.

[0059] The manual mode torque calculation unit 56 includes an MT engine vehicle model. The MT engine 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 paddle 24 when assuming that the electric vehicle 10 is an MT engine vehicle.

[0060] The MT engine vehicle model included in the manual mode torque calculation unit 56 will be described with reference to FIG. 11. As shown in FIG. 11, the MT engine vehicle model includes an engine model 561, a clutch model 562, and a transmission model 563. Note that the engine, clutch, and transmission virtually realized by the MT engine vehicle model are referred to as a virtual engine, a virtual clutch, and a virtual transmission, respectively. In the engine model 561, the virtual engine is modeled. In the clutch model 562, the virtual clutch is modeled. In the transmission model 563, the virtual transmission is modeled.

[0061] The engine model 561 calculates the virtual engine rotational speed Ne and the virtual engine output torque Teout. The virtual engine rotational speed Ne is calculated based on the rotational speed Nw of the wheels, the overall reduction ratio R, and the slip ratio Rslip of the virtual clutch. For example, the virtual engine rotational speed Ne is represented by the following equation (1). Equation (1): Ne = Nw × R / (1 - Rslip)

[0062] The virtual engine output torque Teout is calculated from the virtual engine rotational speed Ne and the accelerator opening Pap. For the calculation of the virtual engine output torque Teout, as shown in FIG. 11, a map defining the relationship among the accelerator opening Pap, the virtual engine rotational speed Ne, and the virtual engine output torque Teout is used. In this map, the virtual engine output torque Teout with respect to the virtual engine rotational speed Ne is given for each accelerator opening Pap. The torque characteristics shown in FIG. 11 can be set to the characteristics assuming a gasoline engine, or can be set to the characteristics assuming a diesel engine. Also, the characteristics assuming a naturally aspirated engine can be set, or the characteristics assuming a supercharged engine can be set.

[0063] The clutch model 562 calculates the 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 normally 0%, and is temporarily opened up 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. 11. In this map, the torque transmission gain k is given with respect to the virtual clutch opening Pc. In FIG. 11, 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 where 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).

[0064] Also, the clutch model 562 calculates the slip ratio Rslip. The slip ratio Rslip is used in the calculation of the virtual engine rotational speed Ne in the engine model 561. To calculate the slip ratio Rslip, a map in which the slip ratio Rslip is given for the virtual clutch opening Pc can be used, similar to the torque transmission gain k.

[0065] The transmission model 563 calculates the gear ratio (shift ratio) r. The gear ratio r is the gear ratio determined by the virtual gear stage GP in the virtual transmission. Upon receiving an upshift operation of the pseudo shift paddle 24, the virtual gear stage GP is shifted up by one stage. On the other hand, upon receiving a downshift operation of the pseudo shift paddle 24, the virtual gear stage GP is shifted down by one stage. The transmission model 563 has a map as shown in FIG. 11. In this map, the gear ratio r is given for the virtual gear stage GP such that the gear ratio r decreases as the virtual gear stage GP increases. The transmission model 563 calculates the transmission output torque Tgout using the gear ratio r obtained from the map and the clutch output torque Tcout. For example, the transmission output torque Tgout is given by 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 shift shock and gives the impression of a vehicle equipped with a stepped transmission.

[0066] The MT engine vehicle model calculates the drive wheel torque Tw using a predetermined reduction ratio rr. The reduction ratio rr is a fixed value determined by the mechanical structure from the virtual transmission to the drive wheels. The value obtained by multiplying the reduction ratio rr by the gear ratio r is the aforementioned overall reduction ratio R. The MT engine vehicle model calculates the drive wheel torque Tw from the transmission output torque Tgout and the reduction ratio rr. For example, the drive wheel torque Tw is given by the product of the transmission output torque Tgout and the reduction ratio rr (Tw = Tgout × rr).

[0067] The control device 50 converts the drive wheel torque Tw calculated in the MT engine vehicle model into the required motor torque Tm. The required motor torque Tm is the motor torque necessary to achieve the drive wheel torque Tw calculated in the MT engine vehicle model. The reduction ratio from the output shaft of the electric motor 44 to the drive wheels is used for the conversion of the drive wheel torque Tw to 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.

[0068] FIG. 12 is a diagram showing a comparison of the torque characteristics of the electric motor 44 realized by motor control using the MT engine vehicle model with the torque characteristics of the electric motor 44 realized by normal motor control as an electric vehicle (EV). According to the motor control using the MT engine vehicle model, as shown in FIG. 12, torque characteristics (solid line in the figure) that simulate the torque characteristics of the MT engine vehicle can be realized according to the virtual gear stage set by the pseudo shift paddle 24. In FIG. 12, the number of gear stages is six.

[0069] 5-2. Second Configuration Example FIG. 13 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 above-described first configuration example will be described. 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 the original shift lever and clutch pedal.

[0070] The pseudo shift lever 27 has a structure that simulates the shift lever of an MT engine vehicle. The arrangement and operating feel of the pseudo shift lever 27 are equivalent to those of an actual MT engine vehicle. The pseudo shift lever 27 is provided with positions corresponding to each gear stage such as first gear, second gear, third gear, fourth gear, fifth gear, sixth gear, 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.

[0071] The pseudo clutch pedal 28 has a structure that simulates the clutch pedal of an MT engine vehicle. The arrangement and operating feel of the pseudo clutch pedal 28 are equivalent to those of an actual MT engine vehicle. The pseudo clutch pedal 28 is operated when the pseudo shift lever 27 is operated. That is, when the driver wants to change the gear stage setting with the pseudo shift lever 27, the driver depresses the pseudo clutch pedal 28, and when the gear stage setting change is completed, the driver stops depressing the pedal 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 depression amount of the pseudo clutch pedal 28.

[0072] Signals from the accelerator position sensor 32, the shift position sensor 27a, the clutch position sensor 28a, the wheel speed sensor 36, and the rotational speed sensor 38 are input to the control device 50. The control device 50 processes these signals and calculates a motor torque command value for PWM control of the inverter 42.

[0073] Similar to the first configuration example described above, the control device 50 includes an automatic mode and a manual mode as control modes. The automatic mode is programmed to continuously change the output of the electric motor 44 according 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 an MT engine vehicle. The manual mode is programmed to change the output of the electric motor 44 according to the operations of the pseudo clutch pedal 28 and the pseudo shift lever 27 with respect to the operation of the accelerator pedal 22. That is, the manual mode is a control mode capable of changing the output of the electric motor 44 in response to the driving operation of manual driving elements other than the accelerator pedal 22 or the brake pedal.

[0074] The vehicle model provided by the manual mode torque calculation unit 56 is the same as that shown in FIG. 11. However, the virtual clutch opening Pc is replaced by the depression amount of the pseudo clutch pedal 28 detected by the clutch position sensor 28a. Further, the virtual gear stage GP is determined by the position of the pseudo shift lever 27 detected by the shift position sensor 27a.

Explanation of Signs

[0075] 10… Electric vehicle, 12… Various sensors, 14… First speaker, 14a~14c… Front speakers, 16… Second speaker, 16a~16b… Rear speakers, 16c~16f… Seat speakers, 18… HMI unit, 22… Accelerator pedal, 24… Pseudo shift paddle, 27… Pseudo shift lever, 28… Pseudo clutch pedal, 44… Electric motor, 100… Sound control device, 102… Processor, 104… Storage device, 110… Information acquisition unit, 120… Vehicle sound source management unit, 130… Engine sound generation unit, 140… Sound output control unit, 150… Sound image setting unit, 200… User terminal, BEV… Information related to electric vehicle, SPK… Information related to speaker settings, EGS… Engine sound data, MDF… Sound pressure adjustment information

Claims

1. A sound control method applied to an electric vehicle using an electric motor as a driving power device, comprising: generating a pseudo engine sound based on operation information of a manual driving element of the electric vehicle; outputting the pseudo engine sound from a plurality of speakers provided in the interior of the electric vehicle; including: the plurality of speakers include a first speaker provided at a front portion of the electric vehicle and a second speaker provided at a location excluding the front portion; the step of outputting the pseudo engine sound further includes adjusting sound pressures of the pseudo engine sound output from the first and second speakers based on sound image setting information in the electric vehicle; A sound control method characterized by the above.

2. The method according to claim 1, wherein: in the step of generating the pseudo engine sound, the pseudo engine sound is generated from sound source data of an engine vehicle designated from among a plurality of vehicle types; the sound image setting information includes information on the mounting position of an engine in the designated engine vehicle; in the step of adjusting each sound pressure, an adjustment is made to increase the sound pressure of the pseudo engine sound output from a speaker provided around the mounting position in the electric vehicle; A sound control method characterized by the above.

3. The method according to claim 2, wherein: in the step of adjusting each sound pressure, an adjustment is made to decrease the sound pressure of the pseudo engine sound output from a speaker other than the speaker provided around the mounting position; A sound control method characterized by the above.

4. The method according to claim 1, wherein: the second speaker includes a rear speaker provided at a rear portion of the electric vehicle; the step of outputting the pseudo engine sound includes: superimposing a pseudo engine intake sound on the pseudo engine sound output from the first speaker; superimposing a pseudo engine exhaust sound on the pseudo engine sound output from the rear speaker; further including: A sound control method characterized by the above.

5. The method according to claim 1, further including, when a change request for the sound image setting information is received, changing the sound image setting information, wherein the change request is input from a terminal provided in the interior of the electric vehicle or a terminal capable of communicating with the electric vehicle; A sound control method characterized by the above.

6. The method according to any one of claims 1 to 5, ​ The manual driving elements include an accelerator pedal and a pseudo shift paddle modeled after the shift paddle of an engine vehicle. A sound control method characterized by this.

7. The method according to any one of Claims 1 to 5, wherein the manual driving elements include an accelerator pedal, a pseudo clutch pedal modeled after the clutch pedal of an engine vehicle, and a pseudo shift lever modeled after the shift lever of an engine vehicle. A sound control method characterized by this.

8. A sound control device applied to an electric vehicle that uses an electric motor as a driving power device, comprising a processor configured to perform various processes, wherein the processor, generates a pseudo engine sound based on operation information of the manual driving elements of the electric vehicle, and outputs the pseudo engine sound to a plurality of speakers provided in the interior of the electric vehicle. It is configured as follows, The plurality of speakers include a first speaker provided at the front portion of the electric vehicle and a second speaker provided at a location excluding the front portion. The processor further, adjusts each sound pressure of the pseudo engine sound output from the first and second speakers based on audio-visual setting information in the electric vehicle. A sound control device characterized by being configured as described above.

9. An electric vehicle that uses an electric motor as a driving power device, including a plurality of speakers provided in the interior of the electric vehicle, and a processor configured to perform various processes, and is provided with, wherein the processor, generates a pseudo engine sound based on operation information of the manual driving elements of the electric vehicle, and outputs the pseudo engine sound to the plurality of speakers. It is configured as follows, The plurality of speakers include a first speaker provided at the front portion of the electric vehicle and a second speaker provided at a location excluding the front portion. The processor further, adjusts each sound pressure of the pseudo engine sound output from the first and second speakers based on audio-visual setting information in the electric vehicle. An electric vehicle characterized by being configured as described above.

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