Vehicle control method, vehicle control device, and electric vehicle

Abstract

Setting information of a driving mode possessed by an electric automobile is acquired. In a case where a mode switch of the driving mode is detected on the basis of the setting information, a notification sound for notifying the driver of the mode switch is output from a speaker. The driving mode includes a self-defining mode of performing at least one of output control of an electric motor based on operation information of a manual driving element of the electric automobile and output control of a simulated engine sound generated on the basis of the operation information. An output form of the notification sound output from the speaker in a case where a switch to the self-defining mode is detected is different from an output form of the notification sound output from the speaker in a case where a switch from the self-defining mode is detected.

Description

Technical Field

[0001] This disclosure relates to technology for use in electric vehicles that use an electric motor as a power source for driving. Background Technology

[0002] Japanese Patent No. 6787507 discloses an electric vehicle that uses an electric motor as a power unit for driving. This conventional electric vehicle controls the output of the electric motor in a manner that simulates the torque characteristics characteristic of a motor vehicle with a manual transmission (hereinafter also referred to as a "MT motor vehicle"). The control of the electric motor's output is based on signals from a simulated manual transmission operated by the driver. The simulated manual transmission has a structure that mimics the manual transmission mounted in an MT motor vehicle.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6787507 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Based on the aforementioned conventional electric vehicles, in addition to the control mode that performs output control of the electric motor based on the driver's manual transmission operation, it is also possible to set a control mode that performs normal output control of the electric motor not based on manual transmission operation as two driving modes for the electric vehicle. Furthermore, if these driving modes are switched based on the driver's specified operation, the driver can obtain the feeling of driving a manual transmission (MT) vehicle at the time and place desired by the driver.

[0008] However, with the increase in the number of driving modes that can be set for electric vehicles, drivers may misunderstand the driving mode they specify. For example, even if a driving mode is specified that controls the output of the electric motor without relying on manual shifting, a driver who misunderstands the mode and manually shifts gears will experience a sense of disharmony with the electric vehicle's behavior. Moreover, this problem is foreseeable to occur when switching driving modes. Therefore, improvements are needed to accurately convey the information about driving mode switching to the driver.

[0009] This disclosure was made in view of the aforementioned issues. One object of this disclosure is to provide a technology that can accurately transmit to the driver the switching of multiple driving modes of an electric vehicle, including control modes for output control of an electric motor based on driver manual transmission operation.

[0010] Methods for solving problems

[0011] The first point of this disclosure is a vehicle control method for electric vehicles that use an electric motor as a power source for driving, and has the following characteristics.

[0012] The vehicle control method includes the following steps: obtaining setting information of the driving mode of the electric vehicle; and when a mode switch of the driving mode is detected based on the setting information, outputting a notification tone from the speaker of the electric vehicle to notify the driver of the mode switch.

[0013] The driving mode includes a custom mode, in which at least one of the output control of the electric motor based on the operation information of the manual driving elements of the electric vehicle and the output control of the simulated engine sound generated based on the operation information is performed.

[0014] The output form of the notification tone from the speaker when a switch to the custom mode is detected is different from the output form of the notification tone from the speaker when a switch from the custom mode is detected.

[0015] The second aspect of this disclosure is a vehicle control device applied to an electric vehicle that uses an electric motor as a power source for driving, and has the following characteristics.

[0016] The vehicle control device includes a processor that performs various processes. The processor obtains setting information for the driving modes of the electric vehicle, and when a mode switch is detected based on the setting information, it outputs a notification tone to the speaker of the electric vehicle to notify the driver of the mode switch.

[0017] The driving mode includes a custom mode, in which at least one of the output control of the electric motor based on the operation information of the manual driving elements of the electric vehicle and the output control of the simulated engine sound generated based on the operation information is performed.

[0018] The output form of the notification tone from the speaker when a switch to the custom mode is detected is different from the output form of the notification tone from the speaker when a switch from the custom mode is detected.

[0019] The third aspect of this disclosure is an electric vehicle that uses an electric motor as a power source for driving, and has the following characteristics.

[0020] The electric vehicle includes a speaker, manual driving elements, and a processor for various processing functions. The processor acquires setting information for the driving modes of the electric vehicle, and upon detecting a mode switch based on the setting information, outputs a notification tone to the speaker of the electric vehicle to inform the driver of the mode switch.

[0021] The driving mode includes a custom mode, in which at least one of the output control of the electric motor based on the operation information of the manual driving elements of the electric vehicle and the output control of the simulated engine sound generated based on the operation information is performed.

[0022] The output form of the notification tone from the speaker when a switch to the custom mode is detected is different from the output form of the notification tone from the speaker when a switch from the custom mode is detected.

[0023] Invention Effects

[0024] According to this disclosure, the output format of the notification tone from the speaker can be changed when a switch from a driving mode other than a custom mode to a custom mode is detected, and the output format of the notification tone from the speaker can be changed when a switch from a custom mode to that other driving mode is detected. Therefore, the start and end of the custom mode can be accurately communicated to the driver. This results in a sense of security regarding the use of the custom mode, thus providing the driver with the feeling gained from driving the engine-driven vehicle in various driving conditions. Attached Figure Description

[0025] Figure 1 This is a conceptual diagram illustrating an electric vehicle and vehicle control device according to an implementation method.

[0026] Figure 2 This is a block diagram representing a first structural example of the power control system of an electric vehicle.

[0027] Figure 3 This is a diagram showing examples of the engine model, clutch model, and transmission model that make up the MT engine vehicle model.

[0028] Figure 4 This graph compares the torque characteristics of an electric motor achieved through motor control using a MT engine vehicle model with the torque characteristics of an electric motor achieved through typical motor control used in electric vehicles.

[0029] Figure 5 This is a block diagram representing a second structural example of the power control system for an electric vehicle.

[0030] Figure 6 This is a block diagram illustrating an example of the functional structure of a vehicle control device related to the output control of simulated engine sound.

[0031] Figure 7 This is another example of a block diagram illustrating the functional structure of a vehicle control device related to the output control of simulated engine sound.

[0032] Figure 8 This is a diagram illustrating the driving modes envisioned in the implementation method.

[0033] Figure 9 This is a block diagram illustrating an example of the functional structure of a vehicle control device related to the output control of notification tones.

[0034] Figure 10 This is another example of a block diagram illustrating the functional structure of a vehicle control device related to the output control of notification tones.

[0035] Figure 11 It is a flowchart illustrating a computer processing flow that is particularly relevant to the implementation method. Detailed Implementation

[0036] The embodiments of this disclosure will be described with reference to the accompanying drawings. It should be noted that in the drawings, the same or equivalent structures are labeled with the same reference numerals and their descriptions are simplified or omitted.

[0037] 1. Overall Structure

[0038] Figure 1 This is a conceptual diagram illustrating an electric vehicle 10 according to an embodiment of the present disclosure and a vehicle control device 100 applied to the electric vehicle 10. The electric vehicle 10 includes an electric motor 44. Examples of electric motors 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 driving.

[0039] The electric vehicle 10 also features various sensors 12. These sensors 12 include operating status sensors such as accelerator position sensors, brake position sensors, and gear position sensors, as well as driving status sensors such as wheel speed sensors, acceleration sensors, and speed sensors. The accelerator position sensor detects the amount of accelerator pedal operation (accelerator opening). The brake position sensor detects the amount of brake pedal operation. The gear position sensor detects the gear position. The wheel speed sensors detect the rotational speed of the wheels of the electric vehicle 10. The acceleration sensors detect the lateral acceleration and longitudinal acceleration of the electric vehicle 10. The speed sensor detects the rotational speed of the electric motor 44.

[0040] The various sensors 12 also include position sensors such as GNSS (Global Navigation Satellite System) sensors, cameras, radar, and identification sensors such as LIDAR (Laser Imaging Detection and Range). GNSS detects the position and attitude of the electric vehicle 10. The camera captures images of at least the front of the electric vehicle 10. Radar and LIDAR identify the surrounding environment of the electric vehicle 10.

[0041] The electric vehicle 10 also includes various switches 14. These switches 14 include operation switches such as turn signal switches, headlight switches, and ignition switches. The turn signal switch toggles the operating state of the turn indicator lights (ON / OFF). The headlight switch toggles the operating state of the headlights (e.g., headlights). The ignition switch toggles the operating state of the electric vehicle 10's power circuit. The various switches 14 also include a mode switching switch for toggling the driving modes of the electric vehicle 10.

[0042] The electric vehicle 10 also includes a speaker 16. The speaker 16 outputs sound into the interior of the electric vehicle 10. The speaker 16 includes, for example, a front speaker located at the front of the interior and a rear speaker located at the rear of the interior. The total number of speakers constituting the speaker 16 and the arrangement of the speaker 16 can be arbitrarily changed.

[0043] The vehicle control unit 100 controls the output of the electric motor 44 to enable the electric vehicle 10 to move. The output control of the electric motor 44 performed by the vehicle control unit 100 includes general control for driving the electric vehicle 10 as a typical electric vehicle and control for driving the electric vehicle 10 in a manner simulating the torque characteristics of a manual transmission (MT) engine vehicle. The latter will be discussed later.

[0044] The vehicle control unit 100 also generates sound (hereinafter referred to as "cabin sound") for output from the speaker 16. The vehicle control unit 100 also outputs the generated cabin sound from the speaker 16. For example, the vehicle control unit 100 generates a simulated engine sound as cabin sound and outputs the generated cabin sound from the speaker 16. In another example, the vehicle control unit 100 generates cabin sound that includes a simulated engine sound and outputs the generated cabin sound from the speaker 16. The output control of the simulated engine sound will be described later.

[0045] The vehicle control unit 100 can also be mounted entirely on the electric vehicle 10. Alternatively, at least a portion of the vehicle control unit 100 can be contained in a management server external to the electric vehicle 10. In this case, the vehicle control unit 100 can also remotely generate interior sound and receive the generated interior sound, outputting it from the speaker 16.

[0046] Generally, the vehicle control device 100 includes at least one processor 102 and at least one storage device 104. The processor 102 performs various processes. Examples of the processor 102 include a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application-Specific Integrated Circuit), and a FPGA (Field-Programmable Gate Array). The storage device 104 stores (saves) various information. Examples of the storage device 104 include volatile memory, non-volatile memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc.

[0047] 2. Output control of electric motor

[0048] The electric motor used in a typical electric vehicle has significantly different torque characteristics compared to the internal combustion engine used in conventional engine vehicles. Due to this difference in torque characteristics, conventional engine vehicles require a transmission, while electric vehicles typically do not. Furthermore, most electric vehicles lack a manual transmission operated by the driver. Therefore, the driving experience differs considerably between a manual transmission (MT) vehicle and an electric vehicle.

[0049] On the other hand, the torque of an electric motor can be relatively easily controlled by adjusting the applied voltage and excitation. Therefore, by implementing appropriate control, the desired torque characteristics can be obtained within the operating range of an electric motor. Utilizing this feature, the torque of an electric vehicle can be controlled to simulate the torque characteristics unique to a manual transmission (MT) vehicle. Furthermore, a simulated manual transmission can be installed in an electric vehicle to allow the driver to experience the driving feel of a MT vehicle. Thus, it is possible to simulate a manual transmission (MT) vehicle within an electric vehicle.

[0050] In this implementation, the output of the electric motor 44 is controlled in a manner that simulates the torque characteristics unique to a manual transmission (MT) engine vehicle. By controlling the output of the electric motor 44, the driver of the electric vehicle 10 can experience a feeling similar to driving a MT engine vehicle. Hereinafter, the control mode of the electric motor 44 used to simulate the torque characteristics unique to a MT engine vehicle will also be referred to as "manual mode". Furthermore, the control mode of the electric motor 44 used to enable the electric vehicle 10 to be driven as a regular electric vehicle will also be referred to as "automatic mode".

[0051] The following describes a structural example of an electric vehicle 10 equipped with a manual mode.

[0052] 2-1. Example of the first structure

[0053] Figure 2 This is a block diagram illustrating a first structural example of the power control system of an electric vehicle 10. The electric vehicle 10 includes an electric motor 44, a battery 46, and an inverter 42. The electric motor 44 is the power unit for driving. The battery 46 stores the electrical energy that drives the electric motor 44. That is, the electric vehicle 10 is a battery electric vehicle (BEV) that uses the electrical energy stored in the battery 46 for driving. The inverter 42 converts the DC power input from the battery 46 during acceleration into driving power for the electric motor 44. Furthermore, the inverter 42 converts the regenerative power input from the electric motor 44 into DC power during deceleration and charges the battery 46.

[0054] The electric vehicle 10 is equipped with an accelerator pedal 22 for the driver to input acceleration requirements for the electric vehicle 10. An accelerator position sensor 32 for detecting the accelerator opening is provided on the accelerator pedal 22.

[0055] The electric vehicle 10 is equipped with simulated paddle shifters 24. These simulated paddle shifters 24 are analog components, distinct from conventional paddle shifters. The simulated paddle shifters 24 have a structure mimicking the paddle shifters found in clutchless manual transmission (MT) vehicles. The simulated paddle shifters 24 are mounted on the steering wheel. The simulated paddle shifters 24 include an upshift switch 34u and a downshift switch 34d, which determine their operating positions. The upshift switch 34u sends an upshift signal by being pulled forward, and the downshift switch 34d sends a downshift signal by being pulled forward.

[0056] Wheel speed sensors 36 are installed on the wheels 26 of the electric vehicle 10. The wheel speed sensors 36 are used as vehicle speed sensors to detect the speed of the electric vehicle 10. In addition, a speed sensor 38 is installed on the electric motor 44 to detect its rotational speed.

[0057] 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 can also be a combination of multiple ECUs. The control device 50 includes an interface, memory, and a processor. An in-vehicle network is connected to the interface. The memory includes RAM for temporarily recording data and ROM for storing programs executable by the processor and various data associated with the programs. The program consists of multiple instructions. The processor reads the program and data from the memory and executes them, generating control signals based on signals obtained from various sensors.

[0058] For example, control unit 50 controls electric motor 44 via PWM control of inverter 42. Signals are input to control unit 50 from accelerometer position sensor 32, analog shift paddles 24, wheel speed sensor 36, speed sensor 38, upshift switch 34u, and downshift switch 34d. Control unit 50 processes these signals and calculates the motor torque command value for PWM control of inverter 42.

[0059] The control device 50 includes an automatic mode and a manual mode as control modes. The automatic mode is the normal control mode for driving the electric vehicle 10 as a typical electric vehicle. The automatic mode is programmed to continuously change the output of the electric motor 44 based on the operation of the accelerator pedal 22. On the other hand, the manual mode is the control mode for driving the electric vehicle 10 like a manual transmission (MT) vehicle. The manual mode is programmed to change the output characteristics of the electric motor 44 relative to the operation of the accelerator pedal 22 based on the operation of the simulated shift paddles 24. In other words, the manual mode is a control mode capable of changing the output of the electric motor 44 in response to driving operations other than the accelerator pedal 22 and the brake pedal.

[0060] The control device 50 includes an automatic mode torque calculation unit 54 and a manual mode torque calculation unit 56. Each unit 54 and 56 can be a separate independent ECU, or the function of an ECU can be obtained by a processor executing a program recorded in memory.

[0061] The automatic mode torque calculation unit 54 has the function of calculating the motor torque when controlling the electric motor 44 in automatic mode. The automatic mode torque calculation unit 54 stores a motor torque command map. The motor torque command map is determined based on the accelerator opening and the rotational speed of the electric motor 44. Signals from the accelerator position sensor 32 and the speed sensor 38 are input to the parameters of the motor torque command map. The motor torque corresponding to these signals is output from the motor torque command map. Therefore, in automatic mode, even if the driver operates the simulated shift paddle 24, this operation is not reflected in the motor torque.

[0062] The manual mode torque calculation unit 56 has an MT engine vehicle model. The MT engine vehicle model is used to calculate the drive wheel torque that should be obtained by operating the accelerator pedal 22 and the simulated shift paddle 24 when the electric vehicle 10 is assumed to be an MT engine vehicle.

[0063] Reference Figure 3 This describes the MT engine vehicle model included in the manual mode torque calculation unit 56. For example... Figure 3As shown, the MT engine vehicle model includes engine model 561, clutch model 562, and transmission model 563. It should be noted that the engine, clutch, and transmission, virtually implemented through the MT engine vehicle model, are respectively referred to as the virtual engine, virtual clutch, and virtual transmission. In engine model 561, the virtual engine is modeled. In clutch model 562, the virtual clutch is modeled. In transmission model 563, the virtual transmission is modeled.

[0064] Engine model 561 calculates the virtual engine speed Ne and the virtual engine output torque Teout. The virtual engine speed Ne is calculated based on the wheel speed Nw, the combined reduction ratio R, and the slip ratio Rslip of the virtual clutch. For example, the virtual engine speed Ne is represented by the following equation (1).

[0065] Formula (1): Ne=Nw×R / (1-Rslip)

[0066] The virtual engine output torque Teout is calculated based on the virtual engine speed Ne and the accelerator opening Pap. In the calculation of the virtual engine output torque Teout, as follows... Figure 3 As shown, a mapping is used that defines the relationship between accelerator opening Pap, virtual engine speed Ne, and virtual engine output torque Teout. In this mapping, each accelerator opening Pap is assigned a virtual engine output torque Teout relative to the virtual engine speed Ne. Figure 3 The torque characteristics shown can be set to the characteristics of a gasoline engine or a diesel engine. Alternatively, they can be set to the characteristics of a naturally aspirated engine or a turbocharged engine.

[0067] Clutch model 562 calculates the torque transmission gain k. The torque transmission gain k is used to calculate the torque transmission degree of the virtual clutch corresponding to the virtual clutch opening Pc. The virtual clutch opening Pc is typically 0%, temporarily opening to 100% in conjunction with the switching of virtual gear stages in the virtual transmission. Clutch model 562 has the following characteristics: Figure 3 The mapping shown is used. In this mapping, the torque transfer gain k is assigned to the virtual clutch opening Pc. Figure 3In the model, 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 the dead zones where the torque transfer gain k does not change according to the virtual clutch opening Pc. Clutch model 562 uses the torque transfer gain k to calculate the clutch output torque Tcout. 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 transfer gain k (Tcout = Teout × k).

[0068] Additionally, clutch model 562 calculates the slip ratio Rslip. The slip ratio Rslip is used to calculate the virtual engine speed Ne in engine model 561. In the calculation of the slip ratio Rslip, similar to the torque transmission gain k, a mapping of the slip ratio Rslip to the virtual clutch opening Pc can be used.

[0069] The transmission model 563 calculates the gear ratio (gear shift ratio) r. The gear ratio r is determined by the virtual gear stage GP in the virtual transmission. When the simulated paddle shifter 24 is activated for an upshift, the virtual gear stage GP shifts up one gear. Conversely, when the simulated paddle shifter 24 is activated for a downshift, the virtual gear stage GP shifts down one gear. The transmission model 563 has the following characteristics: Figure 3 The mapping is shown. In this mapping, the virtual gear stage GP is assigned a gear ratio r such that the larger the virtual gear stage GP, the smaller the gear ratio r. The transmission model 563 uses the gear ratio r obtained from the mapping and the clutch output torque Tcout to calculate the transmission output torque Tgout. 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 varies discontinuously according to the switching of the gear ratio r. This discontinuous variation of the transmission output torque Tgout produces shift shocks, creating the driving feel of a vehicle with a stepped transmission.

[0070] The MT engine vehicle model uses a specified reduction ratio rr to calculate the drive wheel torque Tw. 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 combined reduction ratio R. The MT engine vehicle model calculates the drive wheel torque Tw based on 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).

[0071] The control unit 50 converts the drive wheel torque Tw calculated from the MT engine vehicle model into a required motor torque Tm. The required motor torque Tm is the motor torque needed to achieve the drive wheel torque Tw calculated using the MT engine vehicle model. In the conversion from drive wheel torque Tw to required motor torque Tm, a reduction ratio from the output shaft of the electric motor 44 to the drive wheel is used. Then, the control unit 50 controls the inverter 42 to control the electric motor 44 according to the required motor torque Tm.

[0072] Figure 4 This graph compares the torque characteristics of an electric motor 44 implemented using motor control in a vehicle model with those implemented using typical motor control for an electric vehicle (EV). Based on the motor control using a vehicle model with an MT engine, such as... Figure 4 As shown, torque characteristics similar to those of a simulated manual transmission (MT) engine vehicle can be achieved based on the virtual gear stages set by the simulated shift paddle 24 (solid lines in the figure). It should be noted that... Figure 4 In the middle, the number of gear stages is 6.

[0073] 2-2. Example of the second structure

[0074] Figure 5 This is a block diagram illustrating a second structural example of the powertrain control system of the electric vehicle 10. Here, only the structure different from the first structural example described above will be described. Specifically, in the second structural example, the electric vehicle 10 replaces the simulated shift paddles 24 present in the first structural example with a simulated shift lever 27 and a simulated clutch pedal 28. The simulated shift lever 27 and simulated clutch pedal 28 are simply simulated components different from the original shift lever and clutch pedal.

[0075] The simulated gear shift lever 27 has a structure that mimics the gear shift lever of a manual transmission (MT) vehicle. The configuration and operation of the simulated gear shift lever 27 are identical to those of an actual MT vehicle. The simulated gear shift lever 27 is equipped with positions corresponding to gears such as 1st, 2nd, 3rd, 4th, 5th, 6th, reverse, and neutral. A gear position sensor 27a is installed in the simulated gear shift lever 27, which detects the gear stage by determining the position of the simulated gear shift lever 27.

[0076] The simulated clutch pedal 28 has a structure that simulates the clutch pedal of a manual transmission (MT) engine vehicle. The configuration and operation feel of the simulated clutch pedal 28 are identical to those of an actual MT engine vehicle. The simulated clutch pedal 28 is operated when the simulated shift lever 27 is used. That is, when the driver wants to change the gear setting via the simulated shift lever 27, they depress the simulated clutch pedal 28; when the gear setting change is complete, they depress the pedal, and the simulated clutch pedal 28 returns to its original position. The simulated clutch pedal 28 is equipped with a clutch position sensor 28a for detecting the amount of pressure applied to the simulated clutch pedal 28.

[0077] Signals from the accelerator position sensor 32, gear position sensor 27a, clutch position sensor 28a, wheel speed sensor 36, and speed sensor 38 are input to the control unit 50. The control unit 50 processes these signals and calculates the motor torque command value for PWM control of the inverter 42.

[0078] Similar to the first structural 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 based on 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 relative to the operation of the accelerator pedal 22 based on the operation of the simulated clutch pedal 28 and the simulated gear shift lever 27.

[0079] The vehicle model and manual mode torque calculation unit 56 are equipped with Figure 3 The vehicle model shown is the same. However, the virtual clutch opening Pc is replaced by the amount of pressure applied to the simulated clutch pedal 28 detected by the clutch position sensor 28a. Additionally, the virtual gear stage GP is determined by the position of the simulated gear lever 27 detected by the gear position sensor 27a.

[0080] 3. Simulated engine sound output control

[0081] In implementation, output control that simulates engine sound is used instead of output control of the electric motor, or together with output control of the electric motor. Figure 6 This is a block diagram illustrating an example of the functional structure of a vehicle control device 100 related to the output control of simulated engine sound. The vehicle control device 100 includes 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 as functional blocks related to simulated engine sound. These functional blocks are implemented, for example, through the cooperation of a processor 102 and a storage device 104.

[0082] The information acquisition unit 110 acquires information BEV related to the electric vehicle 10. Information BEV includes information related to the driving status of the electric vehicle 10, information related to the driving environment of the electric vehicle 10, etc. Information BEV is typically detected by various sensors 12, etc. Some of the information related to the driving environment of the electric vehicle 10 can also be acquired by combining information detected by various sensors 12 (e.g., the location information of the electric vehicle 10) with map data.

[0083] Furthermore, the information BEV includes the virtual engine speed Ne. Here, it is assumed that the electric vehicle 10 uses a virtual engine as a power unit for driving. The virtual engine speed Ne is assumed to be the speed of the virtual engine when the electric vehicle 10 is driven by the virtual engine. For example, the information acquisition unit 110 can also calculate the virtual engine speed Ne in a manner that increases with the wheel speed. In addition, when the electric vehicle 10 has a manual mode, the information acquisition unit 110 can also calculate the virtual engine speed Ne in manual mode based on the wheel speed, the combined reduction ratio, and the slip ratio of the virtual clutch. The calculation of the virtual engine speed Ne in manual mode can be performed, for example, using the above formula (1).

[0084] The vehicle audio source management unit 120 stores audio source data EVS for generating simulated engine sounds of an engine vehicle. The vehicle audio source management unit 120 is primarily implemented by the storage device 104. Typically, the audio source data EVS contains various types of audio source data. These various audio source data include, for example, audio source data for sounds caused by engine combustion (for low speed, medium speed, and high speed), audio source data for sounds caused by the operation of drive systems such as gears (for low speed, medium speed, and high speed), noise audio source data, and audio source data for event sounds (such as engine shutdown sound). Each audio source data is pre-generated through simulations based on an engine model and a vehicle model of the engine vehicle. Each audio source data can be flexibly adjusted. That is, at least one of the sound pressure level and frequency of the sound represented by the audio source data can be flexibly adjusted.

[0085] The engine sound generation unit 130 (engine sound simulator) is a simulator that generates simulated engine sounds. The engine sound generation unit 130 obtains at least a portion of the information BEV from the information acquisition unit 110. Specifically, the engine sound generation unit 130 obtains information about the virtual engine speed Ne and vehicle speed from the information acquisition unit 110. Additionally, the engine sound generation unit 130 reads the engine vehicle's audio source data EVS from the vehicle audio source management unit 120. Furthermore, the engine sound generation unit 130 generates simulated engine sounds corresponding to the driving state (virtual engine speed Ne, vehicle speed) of the electric vehicle 10 by combining one or more audio source data contained in the engine vehicle's audio source data EVS. The engine sound data EGS represents the generated simulated engine sound.

[0086] It should be noted that the generation of simulated engine sounds is a known technology, and there are no particular limitations on the methods for generating simulated engine sounds disclosed herein. For example, simulated engine sounds can also be generated using known engine sound simulators used in games, etc. Alternatively, a method could be employed that includes a mapping of virtual engine speed Ne to frequency and a mapping of virtual engine torque to sound pressure, where the frequency of the simulated engine sound is increased or decreased proportionally to the virtual engine speed Ne, and the sound pressure of the simulated engine sound is increased or decreased proportionally to the virtual engine torque.

[0087] The sound output control unit 140 receives engine sound data EGS generated by the engine sound generation unit 130. Furthermore, 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 level of the simulated engine sound by controlling the amplifier. Additionally, the sound output control unit 140 changes the frequency of the simulated engine sound by controlling the FMC (frequency modulator).

[0088] Figure 7 This is another block diagram illustrating the functional structure of a vehicle control device 100 related to the output control of simulated engine sound. Figure 7In the example shown, the vehicle audio source management unit 120 stores audio source data EVS (EVS1, ..., EVSn) for various engine vehicles corresponding to multiple vehicle models (1, ..., n). That is, the vehicle audio source management unit 120 stores the audio source data EVS for each engine vehicle model. The audio source data EVSk (1 ≤ k ≤ n) is pre-generated based on the engine model and vehicle model corresponding to its respective vehicle model. The driver can also specify their preferred vehicle model from among the multiple models. In this case, the engine sound generation unit 130 obtains the audio source data EVSk corresponding to the vehicle model specified by the driver. Then, the engine sound generation unit 130 uses the obtained engine vehicle audio source data EVSk to generate a simulated engine sound. Thus, the driver can experience the feeling of driving their preferred vehicle model.

[0089] 4. Driving mode switching notification

[0090] 4-1. The necessity of switching notifications

[0091] As described above, in this embodiment, at least one of output control of the electric motor and output control simulating engine sound is performed. Therefore, the automatic and manual modes described in the explanation of electric motor output control are further subdivided considering the execution of output control simulating engine sound. Figure 8 This is a diagram illustrating the driving modes envisioned in the implementation method. Figure 8 In the example shown, the automatic mode has a standard EV mode MD0 and a custom EV mode MD2. The manual mode has custom EV modes MD1 and MD3.

[0092] Normal EV mode MD0 and custom EV mode MD1 are driving modes that only control the output of the electric motor. In normal EV mode MD0, normal control is performed to drive the electric vehicle 10 as a regular electric vehicle. In custom EV mode MD1, control for driving the electric vehicle 10 is performed in a manner that simulates the torque characteristics of a manual transmission (MT) engine vehicle. Custom EV mode MD1 is an example of the "custom mode" disclosed herein, also known as MT mode.

[0093] Custom EV modes MD2 and MD3 are driving modes that control the output of simulated engine sounds. Electric motor output control is also performed in Custom EV modes MD2 and MD3. However, the electric motor output control in Custom EV mode MD2 is the same as that in the normal EV mode MD0. Similarly, the electric motor output control in Custom EV mode MD3 is the same as that in Custom EV mode MD2. Custom EV modes MD2 and MD3 are also examples of the "custom modes" disclosed herein. Custom EV mode MD2 is also referred to as a sound mode, and Custom EV mode MD3 is also referred to as MT sound mode.

[0094] Figure 8 The driving mode switching shown occurs between any two driving modes. The switching is based on the driver's intention to switch. For example, the driver may indicate this by operating a mode switch. In another example, the driver may indicate this by a prescribed gesture. In this case, the gesture is identified, for example, by analyzing camera images, thereby confirming the intention. Alternatively, in yet another example, the driver may indicate this by uttering a prescribed sound. In this case, the sound is identified, for example, by analyzing microphone audio, thereby confirming the intention.

[0095] Thus, in the implementation, a standard EV mode and three custom EV modes are envisioned. Therefore, the driver may misunderstand the driving mode switching based on the driver's intention. Consequently, for example, when switching from automatic mode (mode MD0) to manual mode (mode MD1), or from automatic mode (mode MD2) to manual mode (mode MD3), the driver may feel a lack of coordination with the electric vehicle's behavior.

[0096] Therefore, in this implementation, upon detecting a change in driving mode, a notification tone corresponding to the driving mode before or after the switch is output from speaker 16. The driving mode before or after the switch is based on a custom EV mode (mode MD1, MD2, or MD3). Specifically, upon detecting a switch from the normal EV mode MD0 to a custom EV mode (mode MD1, MD2, or MD3), sound data NF1 notifying that the custom EV mode has started is output from speaker 16. Upon detecting a switch from the custom EV mode back to the normal EV mode MD0, sound data NF2 notifying that the custom EV mode has ended is output from speaker 16.

[0097] When a switch between custom EV modes is detected, a notification tone can be output from speaker 16 based on the switched custom EV mode. For example, when a switch from custom EV mode (mode MD2) to custom EV mode (mode MD3) is detected, sound data NF3 notifying that custom EV mode (mode MD3) has started is output from speaker 16.

[0098] Figure 9 This is a block diagram illustrating an example of the functional structure of a vehicle control device 100 related to the output control of notification tones. Figure 9 In the example shown, the vehicle control device 100, in addition to Figure 6 In addition to the information acquisition unit 110 described herein, the system also includes a switching detection unit 150, a notification tone output unit 160, and a notification tone source management unit 170. These functional blocks are implemented, for example, through the cooperation of the processor 102 and the storage device 104.

[0099] The switching detection unit 150 receives driving mode setting information MOD from the information acquisition unit 110. The switching detection unit 150 detects a switching of driving modes based on the setting information MOD. Upon detecting a switching of driving modes, the switching detection unit 150 determines the notification tone data NFS for output to the speaker 16 by referring to the notification tone source management unit 170, which uses the setting information MOD of the driving modes before and after the switching. After determining the notification tone data NFS, the switching detection unit 150 sends it to the notification tone output unit 160.

[0100] The notification tone output unit 160 receives notification tone data NFS from the switching detection unit 150. Then, the notification tone output unit 160 outputs the notification tone data NFS to the speaker 16.

[0101] The notification sound source management unit 170 stores the sound source data for notification tones. The notification sound source management unit 170 is primarily implemented by the storage device 104. Examples of the sound source data for notification tones are sound data NF1, NF2, and NF3. Sound data NF1 is the sound data notifying the end of the normal EV mode MD0 and the start of a custom EV mode (mode MD1, MD2, or MD3). Sound data NF2 is the sound data notifying the end of the custom EV mode (mode MD1, MD2, or MD3) and the start of the normal EV mode MD0. Sound data NF3 is the sound data notifying a switch between two custom EV modes.

[0102] Voice data NF1 may include, for example, a voice indicating the start of the new custom EV mode (e.g., "Entered MT mode," "Entered sound mode"). Voice data NF2 may include, for example, a voice indicating the end of the previous custom EV mode (e.g., "Left MT mode," "Left sound mode"). Voice data NF3 may include, for example, a voice indicating the start of the new custom EV mode (e.g., "Entered sound mode," "Entered MT sound mode"). Thus, there is a possibility that the content of the voice data NF1 is the same as the content of the voice data NF3. On the other hand, the content of the voice data NF1 may not be the same as the content of the voice data NF2.

[0103] Sound data NF1, NF2, and NF3 can also contain simple notification tones (such as buzzers). In this case, sound data NF1 and NF3 can also contain specific fade-in tones. On the other hand, sound data NF2 can contain specific fade-out tones. The fade-in and fade-out tones have different pitches. Therefore, the reproduced tones contained in sound data NF1 and NF3 will not be the same as those contained in sound data NF2.

[0104] Sound data NF1, NF2, and NF3 may also include the engine sound of the vehicle. In this case, sound data NF1 and NF3 may also include the engine sound when the ignition switch of the vehicle is turned on. On the other hand, sound data NF2 may also include the engine sound when the ignition switch of the vehicle is turned off. The pitch of the engine sound when the ignition switch is turned on is different from that when the ignition switch is turned off. Therefore, the engine sound included in sound data NF1 and NF3 will not be the same as the engine sound included in sound data NF2. Sound data NF1 and NF3 may also include the engine sound during acceleration (climbing sound). On the other hand, sound data NF2 may also include the engine sound during deceleration.

[0105] When performing simulated engine sound output control, the engine sounds contained in sound data NF1, NF2 and NF3 can also be generated based on sound source data EVSk corresponding to the vehicle model specified by the driver. Figure 10 This is a block diagram illustrating another example of the functional structure of a vehicle control device 100 related to the output control of notification tones. Figure 10 In the example shown, the switching detection unit 150 uses a reference... Figure 7The vehicle audio source management unit 120, as described above, determines the audio source data EVSk (1≤k≤n) corresponding to the vehicle model specified by the driver. Furthermore, upon detecting a change in driving mode, the switch detection unit 150 uses the driving mode setting information MOD before and after the switch to generate notification tone data NFS (sound data NFk1, NFk2, or NFk3) based on the audio source data EVSk. After generating the notification tone data NFS, the switch detection unit 150 sends it to the notification tone output unit 160.

[0106] The sound data NFk1 and NFk3 may also include the engine sound when the ignition switch is turned on for a vehicle model specified by the driver. In this case, the sound data NFk2 may also include the engine sound when the ignition switch is turned off for a vehicle model specified by the driver. The sound data NFk1 and NFk3 may also include the engine sound during acceleration (climbing sound) for a vehicle model specified by the driver. In this case, the sound data NFk2 may also include the engine sound during deceleration of the engine vehicle.

[0107] 4-2. Processing Example

[0108] Figure 11 It is a flowchart illustrating a computer processing flow that is particularly relevant to the implementation method. Figure 11 The flowchart shown is composed of Figure 1 The processor 102 shown executes repeatedly in a defined control cycle.

[0109] exist Figure 11 In the example shown, firstly, the setting information MOD is obtained (step S11). The setting information MOD is information about the driving mode specified by the driver. As an example of a driving mode... Figure 8 The four modes MD0 to MD3 are described in the text.

[0110] Following step S11, it is determined whether a change in driving mode has been detected (step S12). The determination in step S12 is based on the setting information MOD obtained in step S11. If the determination result in step S12 is positive, steps S13 and S14 are performed. Steps S13 and S14 are used to determine whether the driving mode before or after the switch conforms to the normal EV mode MD0.

[0111] If the determination result of step S13 is positive, it means that the switched driving mode conforms to the custom EV mode (mode MD1, MD2, or MD3). Therefore, if the determination result of step S13 is positive, the sound data NF1 indicating that the custom EV mode has started is output to speaker 16. If the determination result of step S14 is positive, it means that the driving mode before switching conforms to the custom EV mode. Therefore, if the determination result of step S14 is positive, the sound data NF2 indicating that the custom EV mode has ended is output to speaker 16.

[0112] If the determination results of steps S13 and S14 are both negative, it means that a driving mode switch has occurred between the two custom EV modes. Therefore, in this case, the audio data NF3 notifying that a switch has occurred between the custom EV modes is output to the speaker 16.

[0113] 4-3. Effects

[0114] According to the implementation, the output form of the notification tone from speaker 16 when a switch from the normal EV mode MD0 to the custom EV mode is detected can be changed, as can the output form of the notification tone when a switch from the custom EV mode to the normal EV mode MD0 is detected. Therefore, it is possible to accurately convey to the driver that the custom EV mode has started and ended. This relates to the driver's sense of security when using the custom EV mode, and thus provides the driver with the feeling gained from driving the engine vehicle in various driving conditions.

[0115] Explanation of reference numerals in the attached figures

[0116] 10… Electric vehicle, 12… Various sensors, 14… Switch, 16… Speaker, 22… Accelerator pedal, 24… Simulated paddle shifters, 27… Simulated gear shift lever, 28… Simulated clutch pedal, 44… Electric motor, 100… Vehicle control unit, 102… Processor, 104… Storage device, 110… Information acquisition unit, 120… Vehicle audio source management unit, 130… Engine sound generation unit, 140… Sound output control unit, 150… Switching detection unit, 160… Notification tone output unit, BEV… Information related to electric vehicles, EGS… Engine sound data, EVS… Engine vehicle sound source data, MOD… Setting information, NFS… Notification tone data, MD0… Normal EV mode, MD1~MD3… Custom EV mode, NF1~NF3… Notification tone sound data.

Claims

1. A vehicle control method applied to an electric vehicle that uses an electric motor as a power unit for driving, characterized in that, Includes the following steps: Obtain the setting information of the driving modes of the electric vehicle; and If a mode switch is detected based on the aforementioned setting information, a notification tone is output from the electric vehicle's speaker to inform the driver of the mode switch. The driving mode includes a custom mode, in which at least one of the following is performed: output control of the electric motor based on operation information of the manual driving elements of the electric vehicle, and output control of a simulated engine sound generated based on the operation information. The output form of the notification tone from the speaker when a switch to the custom mode is detected is different from the output form of the notification tone from the speaker when a switch from the custom mode is detected.

2. The vehicle control method according to claim 1, characterized in that, The content of the notification tone output from the speaker when a switch to the custom mode is detected is different from the content of the notification tone output from the speaker when a switch from the custom mode is detected.

3. The vehicle control method according to claim 1, characterized in that, If a switch to the custom mode is detected, the notification sound output from the speaker is faded in and reproduced; if a switch from the custom mode is detected, the notification sound output from the speaker is faded out and reproduced.

4. The vehicle control method according to claim 1, characterized in that, The notification tone output from the speaker when a switch to the custom mode is detected, and the notification tone output from the speaker when a switch from the custom mode is detected, include the engine sound of a specified engine vehicle.

5. The vehicle control method according to claim 4, characterized in that, The notification tone output from the speaker upon detecting a switch to the custom mode includes the engine sound when the ignition switch of the specified engine vehicle is turned on. The notification tone output from the speaker upon detection of a switch from the custom mode includes the engine sound when the ignition switch of the specified engine vehicle is turned off.

6. The vehicle control method according to claim 4, characterized in that, The notification tone output from the speaker upon detecting a switch to the custom mode includes the engine sound during acceleration of the specified engine vehicle. The notification tone output from the speaker upon detecting a switch from the custom mode includes the engine sound of the specified engine vehicle during deceleration.

7. The vehicle control method according to claim 4, characterized in that, The specified engine vehicle is an engine model designated from a variety of engine models. The notification tone output from the speaker when a switch to the custom mode is detected, and the notification tone output from the speaker when a switch from the custom mode is detected, include the engine sound of the specified engine model.

8. The method according to any one of claims 1 to 7, characterized in that, The manual driving elements include an accelerator pedal and simulated paddle shifters, which mimic the paddle shifters of an engine vehicle.

9. The method according to any one of claims 1 to 7, characterized in that, The manual driving elements include an accelerator pedal, a simulated clutch pedal, and a simulated gear shift lever. The simulated clutch pedal mimics the clutch pedal of an engine vehicle, and the simulated gear shift lever mimics the gear shift lever of an engine vehicle.

10. A vehicle control device applied to an electric vehicle that uses an electric motor as a power source for driving, characterized in that, A processor capable of performing various processing tasks. The processor obtains the setting information of the driving mode of the electric vehicle. When the processor detects a mode switch in the driving mode based on the configured information, it outputs a notification tone to the speaker of the electric vehicle to inform the driver of the mode switch. The driving mode includes a custom mode, in which at least one of the following is performed: output control of the electric motor based on operation information of the manual driving elements of the electric vehicle, and output control of a simulated engine sound generated based on the operation information. The output form of the notification tone from the speaker when a switch to the custom mode is detected is different from the output form of the notification tone from the speaker when a switch from the custom mode is detected.

11. An electric vehicle that uses an electric motor as a power unit for driving, characterized in that, have: speaker; Manual driving elements; and The processor performs various processing tasks. The processor obtains the setting information of the driving mode of the electric vehicle. When the processor detects a mode switch in the driving mode based on the configured information, it outputs a notification tone to the speaker to inform the driver of the electric vehicle of the mode switch. The driving mode includes a custom mode, in which at least one of the following is performed: output control of the electric motor based on the operation information of the manual driving elements, and output control of a simulated engine sound generated based on the operation information. The output form of the notification tone from the speaker when a switch to the custom mode is detected is different from the output form of the notification tone from the speaker when a switch from the custom mode is detected.

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