Sound management systems, electric vehicles, and sound management programs

Abstract

To provide a sound management system, an electric vehicle, and a sound management program which enhance the satisfaction of a driver having a desire for more reality than before when a pseudo engine sound is output via a speaker mounted in the electric vehicle.SOLUTION: A sound management system is applied to an electric vehicle using an electric motor as a power unit for traveling, generates a pseudo engine sound so as to output the pseudo engine sound via a speaker mounted in the electric vehicle, and acquires driving history information indicating a driving history of the electric vehicle so as to change the pseudo engine sound according to the driving history.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to sound management technology applied to electric vehicles that use an electric motor as a driving power plant. [Background Art]

[0002] Patent Document 1 discloses a sound control device mounted on a vehicle that can travel driven by an electric motor. The sound control device realistically reproduces engine sounds generated during shift changes in engine vehicles. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2011-215437 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Engine sounds of actual engine vehicles change over time. The causes of such temporal changes in engine sounds are not limited to aging degradation of components. As a driver uses an engine vehicle over a long period of time, the driver's driving style and driving environment may also be reflected in the engine sound. In other words, as the driver uses the engine vehicle extensively, the engine sound becomes "matured". Since driving styles and driving environments differ among drivers, the maturation state of engine sounds also differs among drivers. The maturation state of an engine sound is unique to the driver and represents the driver's individuality. Some drivers feel pleasure and pride in such maturation of engine sounds.

[0005] The above-mentioned Patent Document 1 does not take into account temporal changes (maturation) of engine sounds. Accordingly, it cannot increase the satisfaction of drivers who seek higher realism. [Means for Solving the Problem]

[0006] The first aspect relates to sound management systems applied to electric vehicles that use electric motors as the power source for propulsion. The sound management system comprises one or more processors. One or more processors generate a simulated engine sound and output the simulated engine sound through speakers installed in the electric vehicle. One or more processors acquire driving history information indicating the driving history of the electric vehicle and change the simulated engine sound according to the driving history.

[0007] The second perspective relates to electric vehicles, which use electric motors as the power source for propulsion. The electric vehicle is equipped with one or more processors. The one or more processors generate a simulated engine sound and output the simulated engine sound through speakers installed in the electric vehicle. The one or more processors acquire driving history information indicating the driving history of the electric vehicle and change the simulated engine sound according to the driving history.

[0008] The third aspect relates to sound management programs applied to electric vehicles that use electric motors as the power source for propulsion. The sound management program, executed by a computer, performs engine sound output processing. The engine sound output processing includes generating a simulated engine sound and outputting it through speakers installed in the electric vehicle. The engine sound output processing further includes acquiring driving history information indicating the driving history of the electric vehicle and changing the simulated engine sound according to the driving history. [Effects of the Invention]

[0009] According to this disclosure, a simulated engine sound is output through a speaker installed in the electric vehicle. This simulated engine sound changes according to the electric vehicle's driving history. Therefore, it is possible to increase the satisfaction of drivers who seek greater realism. [Brief explanation of the drawing]

[0010] [Figure 1]This is a conceptual diagram showing an electric vehicle and a sound management system. [Figure 2] This block diagram shows an example of the basic functional configuration of a sound management system. [Figure 3] This block diagram shows another example of the basic functional configuration of a sound management system. [Figure 4] This diagram illustrates various examples of how the engine noise of a typical gasoline-powered car changes over time. [Figure 5] This is a block diagram showing an example of the functional configuration of a sound management system. [Figure 6] This is a block diagram showing an example configuration of a sound source adjustment model. [Figure 7] This block diagram shows another example of the functional configuration of a sound management system. [Figure 8] This is a block diagram showing yet another example of the functional configuration of a sound management system. [Figure 9] This is a block diagram showing yet another example of the functional configuration of a sound management system. [Figure 10] This is a block diagram illustrating the in-vehicle equipment and management server. [Figure 11] This is a block diagram illustrating a first example of how the sound management system is operated. [Figure 12] This is a block diagram illustrating a second example of how the sound management system is operated. [Figure 13] This is a block diagram illustrating a third example of how the sound management system is operated. [Figure 14] This is a block diagram illustrating a fourth example of how the sound management system is operated. [Figure 15] This is a block diagram showing a first example configuration of a power control system for an electric vehicle. [Figure 16] This figure shows examples of the engine model, clutch model, and transmission model that make up an MT vehicle model. [Figure 17] This figure shows the torque characteristics of an electric motor achieved through motor control using an MT vehicle model. [Figure 18]It is a block diagram showing a second configuration example of a power control system for an electric vehicle.

Mode for Carrying Out the Invention

[0011] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0012] 1. Output of pseudo engine sound Figure 1 is a conceptual diagram showing an electric vehicle 10 and a sound management system 100 according to the present embodiment. 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 power device for traveling.

[0013] The electric vehicle 10 also includes various sensors 11. The various sensors 11 detect the driving state of the electric vehicle 10. Examples of the various sensors 11 include an accelerator position sensor, a brake position sensor, a wheel speed sensor, an acceleration sensor, a rotation speed sensor, a position sensor, a temperature sensor, and a humidity sensor. The accelerator position sensor detects an operation amount of an accelerator pedal. The brake position sensor detects an operation amount of a brake pedal. The wheel speed sensor detects the rotation speed of the wheels of the electric vehicle 10. The acceleration sensor detects lateral acceleration and longitudinal acceleration of the electric vehicle 10. The rotation speed sensor detects the rotation speed of the electric motor 44. The position sensor detects the position of the electric vehicle 10. A GNSS (Global Navigation Satellite System) sensor is exemplified as the position sensor. The temperature sensor detects the temperature inside and outside the electric vehicle 10. The humidity sensor detects the humidity inside and outside the electric vehicle 10.

[0014] Furthermore, the electric vehicle 10 is equipped with one or more speakers 70. For example, the speaker 70 is an in-vehicle speaker that outputs sound into the cabin of the electric vehicle 10. As another example, the speaker 70 may be an out-of-vehicle speaker that outputs sound outside the electric vehicle 10. The electric vehicle 10 may include both an in-vehicle speaker and an out-of-vehicle speaker.

[0015] The sound management system 100 is applied to such an electric vehicle 10 and manages the sounds related to the electric vehicle 10. In particular, the sound management system 100 generates and manages the sounds output from the speaker 70 installed in the electric vehicle 10. The sound management system 100 also outputs the generated sounds through the speaker 70 installed in the electric vehicle 10. For example, the sound management system 100 generates a simulated engine sound and outputs the simulated engine sound through the speaker 70 installed in the electric vehicle 10.

[0016] The entire sound management system 100 may be installed in the electric vehicle 10. As another example, at least a part of the sound management system 100 may be contained in an external management server outside the electric vehicle 10. In that case, the sound management system 100 may remotely manage sounds related to the electric vehicle 10. As yet another example, the sound management system 100 may be distributed between the electric vehicle 10 and the management server.

[0017] Generally speaking, the sound management system 100 includes one or more processors 101 (hereinafter simply referred to as processor 101) and one or more storage devices 102 (hereinafter simply referred to as storage devices 102). The processor 101 performs various processes. Examples of processors 101 include general-purpose processors, application-specific processors, CPUs (Central Processing Units), GPUs (Graphics Processing Units), ASICs (Application Specific Integrated Circuits), FPGAs (Field-Programmable Gate Arrays), integrated circuits, conventional circuits, and / or combinations thereof. The processor 101 can also be called circuitry or processing circuitry. Circuitry is hardware programmed to realize the described functions, or hardware that performs the functions. The storage devices 102 store (store) various information. Examples of storage devices 102 include volatile memory, non-volatile memory, HDDs (Hard Disk Drives), SSDs (Solid State Drives), etc. The functions of the sound management system 100 are realized through the cooperation of the processor 101 and the storage devices 102.

[0018] One or more sound management programs 105 (hereinafter simply referred to as sound management program 105) are computer programs executed by the processor 101. The functions of the sound management system 100 may be realized through the cooperation of the processor 101 executing the sound management program 105 and the storage device 102. The sound management program 105 is stored in the storage device 102. Alternatively, the sound management program 105 may be recorded on a computer-readable recording medium.

[0019] Figure 2 is a block diagram showing an example of the basic functional configuration of the sound management system 100. The sound management system 100 includes, as functional blocks, a driving information acquisition unit 110, a sound source data management unit 120, an engine sound generation unit 130, and an output unit 140. These functional blocks may be realized through the cooperation of a processor 101 that executes the sound management program 105 and a storage device 102.

[0020] The driving information acquisition unit 110 acquires driving information DRV related to the electric vehicle 10. The driving information DRV includes information about the driver's driving operations, information about the driving state of the electric vehicle 10, information about the driving environment in which the electric vehicle 10 is located, etc. Typically, the driving information DRV includes sensor detection information detected by sensors 11 mounted on the electric vehicle 10. For example, the sensor detection information includes the amount of accelerator pedal operation (accelerator opening), the amount of brake pedal operation (brake opening), wheel speed, vehicle speed, longitudinal acceleration, lateral acceleration, rotational speed of the electric motor 44, etc. The sensor detection information may also include the position of the electric vehicle 10. The sensor detection information may also include temperature and humidity.

[0021] Furthermore, the driving information DRV includes the virtual engine rotation speed Ne. Here, it is assumed that the electric vehicle 10 uses a virtual engine as the power source for driving. The virtual engine rotation speed Ne is the rotation speed of the virtual engine when it is assumed that the electric vehicle 10 is driven by the virtual engine. For example, the driving information acquisition unit 110 may calculate the virtual engine rotation speed Ne so that it increases as the wheel speed increases. Also, if the electric vehicle 10 has a manual mode (MT mode) as described later, the driving information acquisition unit 110 may calculate the virtual engine rotation speed Ne in 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 rotation speed Ne in manual mode will be described later.

[0022] The sound source data management unit 120 stores and manages basic sound source data 200 used to generate simulated engine sounds. The sound source data management unit 120 is mainly implemented by one or more storage devices 102. Typically, the basic sound source data 200 includes multiple types of sound source data. These multiple types of sound source data include, for example, sound source data for sounds caused by engine combustion (for low, medium, and high rotational speeds), sound source data for sounds caused by the drive system such as gears (for low, medium, and high rotational speeds), noise sound source data, event sound (e.g., grinding noise, engine stall sound) sound source data, etc. Each sound source data is pre-generated through simulations based on engine models and vehicle models of engine-powered vehicles. 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 can be flexibly adjusted.

[0023] The engine sound generation unit 130 (engine sound simulator) is a simulator that generates a simulated engine sound. The engine sound generation unit 130 acquires at least a portion of the driving information DRV from the driving information acquisition unit 110. In particular, the engine sound generation unit 130 acquires information on the virtual engine rotation speed Ne and vehicle speed from the driving information acquisition unit 110. The engine sound generation unit 130 also reads the basic sound source data 200 from the sound source data management unit 120. Then, the engine sound generation unit 130 generates a simulated engine sound corresponding to the driving state of the electric vehicle 10 (virtual engine rotation speed Ne and vehicle speed) by combining one or more sound source data included in the basic sound source data 200. The engine sound data ES is data that indicates the generated simulated engine sound.

[0024] Furthermore, the generation of simulated engine sounds is a well-known technique and is not particularly limited in this embodiment. For example, simulated engine sounds may be generated using a well-known engine sound simulator used in games, etc. Alternatively, one could have a map of virtual engine rotation speed Ne-frequency and a map of virtual engine torque-sound pressure, and increase or decrease the frequency of the simulated engine sound in proportion to the virtual engine rotation speed Ne, and increase or decrease the sound pressure in proportion to the virtual engine torque.

[0025] The output unit 140 receives engine sound data ES generated by the engine sound generation unit 130. Based on the engine sound data ES, the output unit 140 outputs a simulated engine sound through the speaker 70.

[0026] Figure 3 is a block diagram showing another example of the basic functional configuration of the sound management system 100. In the example shown in Figure 3, the sound source data management unit 120 stores and manages multiple types of basic sound source data 200 (200-A, 200-B, 200-C, etc.) corresponding to each of multiple vehicle types (A, B, C, etc.). In other words, the sound source data management unit 120 stores and manages basic sound source data 200 for each vehicle type. Each basic sound source data 200 is pre-generated based on the engine model and vehicle model of the corresponding vehicle type. The driver may specify their preferred vehicle type from among the multiple vehicle types. In that case, the engine sound generation unit 130 acquires one of the multiple types of basic sound source data 200 that corresponds to the vehicle type specified by the driver. Then, the engine sound generation unit 130 generates a simulated engine sound using the acquired basic sound source data 200 (e.g., basic sound source data 200-B corresponding to vehicle type B). This allows the driver to get the feeling that they are driving their preferred vehicle type.

[0027] 2. Reproduction of the aging (maturation) of engine sound. Vehicles equipped with an engine (internal combustion engine) and using the engine as the power source for propulsion will be referred to as "engine cars" below. The actual engine sound of an engine car changes over time. The cause of this change in engine sound is not solely due to the deterioration of parts over time. As a driver uses an engine car, their driving style and driving environment can be transferred to (reflected in) the engine sound. In other words, as a driver uses an engine car, the engine sound "matures." Since driving styles and driving environments differ from driver to driver, the state of engine sound maturation also differs from driver to driver. The state of engine sound maturation is unique to the driver and reflects the driver's personality. Some drivers feel joy and pride in such engine sound maturation.

[0028] Therefore, this disclosure proposes a technology that can reproduce the changes (maturation) of engine sound in gasoline-powered vehicles over time.

[0029] 2-1. Examples of changes in engine noise over time Figure 4 illustrates various examples of how engine noise in a typical gasoline-powered vehicle changes over time. Parameter Px is a parameter that contributes to the aging of engine noise in a gasoline-powered vehicle. In the electric vehicle 10, the state of aging changes in the engine noise of a virtual engine can be estimated from the history of parameter Px (or an equivalent parameter).

[0030] 2-1-1. Example 1 Driving styles vary from driver to driver. Some drivers tend to use the engine at relatively high RPMs, while others tend to use it at relatively low RPMs. It is known that differences in the preferred engine speed gradually lead to differences in how the engine sound of a gasoline-powered car changes over time. In other words, differences in drivers' driving styles manifest as differences in how the engine sound of a gasoline-powered car changes (matures) over time.

[0031] In the first example, the first parameter Px1 that contributes to the aging of engine noise is the engine speed. If the history of the first parameter Px1 (engine speed) is different, gradual differences will arise in the aging of the engine noise of the engine-powered vehicle. In the electric vehicle 10, a virtual engine speed Ne, which corresponds to the engine speed, is used as the first parameter Px1. Then, from the history of the virtual engine speed Ne, the aging of the engine noise of the virtual engine can be estimated.

[0032] 2-1-2. Second Example Depending on how a gasoline-powered car is driven and how the vehicle is tilted, the engine mounts can easily wear out (deteriorate). It is known that as engine mounts wear out, a low-pitched booming sound or other abnormal noises increase. In other words, differences in the driver's driving style and driving environment manifest as differences in the aging (maturation) of the engine sound of a gasoline-powered car.

[0033] For example, frequent steering maneuvers that exert strong lateral G-forces on the vehicle body can easily degrade the engine mounts. Another example is frequent acceleration or braking that exerts strong longitudinal G-forces on the vehicle body; these can also easily degrade the engine mounts. Yet another example is frequent sudden acceleration; and yet another example is frequent sudden braking; these can also easily degrade the engine mounts. In these cases, the second parameter Px2 that contributes to the aging of the engine noise is lateral acceleration, longitudinal acceleration, jerk, etc.

[0034] As another example, poor clutch engagement by the driver can easily lead to deterioration of the engine mounts. In other words, if the gear shift timing, clutch position, and engine speed are not in the correct combination, the engine mounts are more likely to deteriorate. In this case, the second parameter Px2 that contributes to the aging of the engine sound is the combination of gear shift timing, clutch position, and engine speed.

[0035] As another example, if a gasoline-powered vehicle is frequently driven on steep inclines, the engine mounts are more likely to deteriorate. Similarly, if a gasoline-powered vehicle is parked on an inclined road for extended periods, the engine mounts are also more likely to deteriorate. In this case, the second parameter Px2 that contributes to the aging of the engine noise is the vehicle's tilt. The vehicle's tilt can be estimated using an acceleration sensor mounted on the vehicle.

[0036] If the histories of these second parameters Px2 differ, gradual differences will also arise in the aging process of the engine sound of a gasoline-powered vehicle. In an electric vehicle 10, the aging process of the engine sound of a virtual engine can be estimated from the history of the second parameter Px2 (or an equivalent parameter).

[0037] 2-1-3. Third Example As an engine-powered vehicle is driven, the sliding parts of the engine stabilize compared to its initial state immediately after manufacture, and the engine returns to its intended state. As the sliding parts stabilize, the engine sound also changes. In the third example, the third parameter Px3 that contributes to the aging change of the engine sound is either driving time or driving distance. The driving time history is the total driving time, and the driving distance history is the total driving distance. If the history of the third parameter Px3 is different, gradual differences will arise in the aging change of the engine sound of the engine-powered vehicle. In the electric vehicle 10, the aging change of the engine sound of the virtual engine can be estimated from the history of the third parameter Px3.

[0038] 2-1-4. The fourth example As an engine-powered vehicle is driven, the materials in the intake system stabilize compared to the initial state immediately after manufacture, and the engine sound changes. For example, it is known that the engine sound improves as the water content of the resin material decreases. In the fourth example, the fourth parameter Px4 that contributes to the aging change of the engine sound is the driving time or distance, humidity, temperature, etc. If the history of the fourth parameter Px4 is different, the state of the aging change of the engine sound of the engine-powered vehicle will gradually differ. In the electric vehicle 10, the state of the aging change of the engine sound of the virtual engine can be estimated from the history of the fourth parameter Px4.

[0039] 2-1-5. The fifth example As engine combustion becomes incomplete, carbon deposits accumulate inside the engine. These deposits accumulate in areas such as the piston head, valves, and exhaust port. This carbon buildup changes the compression ratio and consequently alters the engine's sound. In other words, differences in a driver's driving style and driving environment manifest as differences in the aging and evolution of an engine's sound.

[0040] For example, if a driver drives an engine car slowly at low RPMs, incomplete combustion is likely to increase. In this case, the fifth parameter Px5 that contributes to the aging of the engine sound is engine speed, longitudinal acceleration, etc.

[0041] As another example, at high altitudes, the lower atmospheric pressure makes engines more prone to incomplete combustion when driving at high altitudes. In this case, the fifth parameter Px5 that contributes to the aging of engine noise is the vehicle's altitude. Altitude is obtained, for example, based on the vehicle's position and 3D map information. The vehicle's position is obtained by a GNSS sensor mounted on the vehicle.

[0042] If the histories of these fifth parameters Px5 differ, gradual differences will arise in the aging process of the engine sound of a gasoline-powered vehicle. In the electric vehicle 10, the aging process of the engine sound of the virtual engine can be estimated from the history of the fifth parameter Px5 (or an equivalent parameter). In the electric vehicle 10, the virtual engine rotation speed Ne is used instead of the engine rotation speed.

[0043] 2-1-6. Example 6 If a gasoline-powered vehicle's engine ECU is equipped with a knock detection mechanism, the ECU learns how the driver uses the accelerator pedal, and as a result, changes are made to the ignition timing, etc. For example, the combustion timing may be advanced or delayed. Or, the amount of fuel may be subtly adjusted. This changes the sound of the gasoline-powered vehicle's engine. In other words, the driver's "habits" are reflected in the sound of the gasoline-powered vehicle's engine.

[0044] In the sixth example, the sixth parameter Px6 that contributes to the aging of the engine sound is the accelerator pedal operation amount, engine rotational speed, etc. If the history of the sixth parameter Px6 is different, gradual differences will arise in the aging of the engine sound of the gasoline car. In the electric vehicle 10, the aging of the engine sound of the virtual engine can be estimated from the history of the sixth parameter Px6. In the electric vehicle 10, the virtual engine rotational speed Ne is used instead of the engine rotational speed.

[0045] 2-2. Example of Functional Configuration Figure 5 is a block diagram showing an example of the functional configuration of the sound management system 100 according to this embodiment. In addition to the functional blocks shown in Figure 2, the sound management system 100 further includes an operation history management unit 150 and a sound source adjustment unit 160. These functional blocks may be realized through the cooperation of a processor 101 that executes the sound management program 105 and a storage device 102.

[0046] The driving history management unit 150 stores and manages driving history information HST, which shows the driving history of the electric vehicle 10. More specifically, the driving history management unit 150 acquires driving information DRV related to the electric vehicle 10 from the driving information acquisition unit 110 described above. As described above, the driving information DRV includes sensor detection information detected by sensors 11 mounted on the electric vehicle 10. The driving information DRV also includes the virtual engine rotation speed Ne. The driving history information HST corresponds to the history of the driving information DRV.

[0047] In particular, the driving information DRV includes a parameter Px (or an equivalent parameter) that contributes to the aging of the engine noise of the engine vehicle as described in Section 2-1 above. The driving history management unit 150 may manage the history of each parameter Px. In other words, the driving history management unit 150 may generate and manage driving history information HST for each parameter Px. For example, the driving history information HST for each parameter Px may be managed in histogram format.

[0048] The driving history management unit 150 acquires driving information DRV from the driving information acquisition unit 110 at regular intervals. Each time the driving history management unit 150 acquires driving information DRV, it updates the driving history information HST based on the acquired driving information DRV.

[0049] The sound source adjustment unit 160 acquires driving history information HST from the driving history management unit 150 and adjusts (updates) the basic sound source data 200 according to the driving history of the electric vehicle 10. As described above, at least one of the sound pressure and frequency of the sound provided by the basic sound source data 200 can be flexibly adjusted. By adjusting (updating) the basic sound source data 200 according to the driving history, the simulated engine sound generated based on the basic sound source data 200 can be changed according to the driving history. In other words, the simulated engine sound can be aged (matured) according to the driving history of the electric vehicle 10.

[0050] More specifically, the sound source adjustment unit 160 includes a sound source adjustment model 165. The sound source adjustment model 165 is a model that determines how to adjust the basic sound source data 200 in relation to the driving history of the electric vehicle 10. For example, the sound source adjustment model 165 determines how to adjust the basic sound source data 200 in comparison to the initial state. Alternatively, the sound source adjustment model 165 may determine how to adjust the basic sound source data 200 in comparison to the current state. The sound source adjustment model 165 is pre-generated through simulations based on engine models and vehicle models of gasoline-powered vehicles. The sound source adjustment model 165 is generated for each vehicle type.

[0051] The adjustment information ADJ indicates how the basic sound source data 200 should be adjusted. For example, the adjustment information ADJ indicates how the basic sound source data 200 should be adjusted compared to the initial state. Alternatively, the adjustment information ADJ may indicate how the basic sound source data 200 should be adjusted compared to the current state. The sound source adjustment unit 160 acquires the operation history information HST and acquires the adjustment information ADJ corresponding to the operation history information HST by using the sound source adjustment model 165.

[0052] Figure 6 is a block diagram showing an example configuration of the sound source adjustment model 165. The sound source adjustment model 165 includes multiple models 166 and an integration unit 167. In the example shown in Figure 6, the multiple models 166 include the first to sixth models 166-1 to 166-6. The first to sixth models 166-1 to 166-6 are models for estimating the aging of engine noise in the first to sixth examples described in Section 2-1 above.

[0053] Model 166-1 takes the history of the first parameter Px1 (virtual engine rotation speed Ne) as input. Based on the history of the first parameter Px1, Model 166-1 estimates the state of age-related changes in the engine sound of the virtual engine. Model 266-2 takes the history of the second parameter Px2 as input. Based on the history of the second parameter Px2, Model 266-2 estimates the state of age-related changes in the engine sound of the virtual engine. Model 366-3 takes the history of the third parameter Px3 as input. Based on the history of the third parameter Px3, Model 366-3 estimates the state of age-related changes in the engine sound of the virtual engine. Model 46-4 takes the history of the fourth parameter Px4 as input. Based on the history of the fourth parameter Px4, Model 46-4 estimates the state of age-related changes in the engine sound of the virtual engine. Model 56-5 takes the history of the fifth parameter Px5 as input. Model 5, 166-5, estimates the state of age-related changes in the engine sound of a virtual engine based on the history of the fifth parameter, Px5. Model 6, 166-6, takes the history of the sixth parameter, Px6, as input. Model 6, 166-6, estimates the state of age-related changes in the engine sound of a virtual engine based on the history of the sixth parameter, Px6. Each model 166 is pre-generated through simulations based on engine models and vehicle models of engine-powered vehicles.

[0054] The integration unit 167 integrates the results output from the first to sixth models 166-1 to 166-6 to obtain the overall state of the engine sound's aging process. For example, the state of the engine sound's aging process is represented by the change in engine sound (sound pressure, frequency) compared to the initial state. Alternatively, the state of the engine sound's aging process may be represented by the change in engine sound (sound pressure, frequency) compared to the current state after the last update. Based on the overall state of the engine sound's aging process, the integration unit 167 obtains adjustment information ADJ, which indicates how to adjust the basic sound source data 200. An algorithm for converting the state of the engine sound's aging process into adjustment information ADJ is also created in advance through simulation.

[0055] The integration unit 167 may store the adjustment information ADJ so that it can track the changes in the adjustment information ADJ over time. In other words, the integration unit 167 may store the adjustment information ADJ(0) to ADJ(N) at various timings. The adjustment information ADJ(0) is the oldest, and the adjustment information ADJ(N) is the most recent.

[0056] Furthermore, the sound source adjustment model 165 is generated for each vehicle model. As illustrated in Figure 3, when a driver specifies their preferred vehicle model, one of the multiple types of basic sound source data 200 corresponding to the vehicle model specified by the driver is used to generate the simulated engine sound. In this case, the sound source adjustment model 165 used is also the one corresponding to the vehicle model specified by the driver.

[0057] The sound source adjustment unit 160 outputs adjustment information ADJ to the sound source data management unit 120. The sound source data management unit 120 updates the basic sound source data 200 used to generate the simulated engine sound according to the adjustment information ADJ. In this way, it becomes possible to age (mature) the simulated engine sound according to the driving history of the electric vehicle 10.

[0058] The update frequency of the base sound source data 200 is arbitrary. For example, the base sound source data 200 may be updated at regular intervals (e.g., weekly, monthly, or every few months). Alternatively, the base sound source data 200 may be updated in near real-time.

[0059] As shown in Figure 5, the sound source data management unit 120 may store the basic sound source data 200 so that the changes in the basic sound source data 200 can be observed. In other words, the sound source data management unit 120 may store basic sound source data 200(0) to 200(N) at various timings. Basic sound source data 200(0) is the initial state, and basic sound source data 200(N) is the latest version. The sound source data management unit 120 provides the latest basic sound source data 200(N) to the engine sound generation unit 130. The engine sound generation unit 130 generates a simulated engine sound using the latest basic sound source data 200(N). In this way, the simulated engine sound can be changed (matured) over time according to the driving history of the electric vehicle 10.

[0060] Furthermore, the sound source data management unit 120 does not necessarily need to store all past basic sound source data 200. For example, the sound source data management unit 120 may store only the latest basic sound source data 200(N). This saves storage capacity in the storage device 102.

[0061] The sound source data management unit 120 may store at least both the initial basic sound source data 200(0) and the latest basic sound source data 200(N). In this case, it becomes possible to compare the simulated engine sound in the initial state with the simulated engine sound after maturation.

[0062] Figure 7 is a block diagram showing another example of the functional configuration of the sound management system 100. In the example shown in Figure 7, the sound management system 100 further includes a user interface 170. The user interface 170 includes input and output devices. Examples of input devices include a touch panel, buttons, switches, a keyboard, a microphone, etc. The sound source data management unit 120 stores multiple types of basic sound source data 200(0) to 200(N) at various timings. The user (driver) of the electric vehicle 10 specifies which timing of simulated engine sound they want via the user interface 170. The sound source data management unit 120 selects a basic sound source data 200(S) from the basic sound source data 200(0) to 200(N) at the timing specified by the driver or close to it. The sound source data management unit 120 provides the selected basic sound source data 200(S) to the engine sound generation unit 130. The engine sound generation unit 130 Selected basic sound source data 200(S) It generates simulated engine sounds based on [a specific set of parameters]. The user (driver) can switch between simulated engine sounds depending on their mood. Furthermore, the user (driver) can compare and contrast various simulated engine sounds.

[0063] Figure 8 is a block diagram showing yet another example of the functional configuration of the sound management system 100. In the example shown in Figure 8, the sound management system 100 has several different modes for maturing the simulated engine sound. Specifically, the first mode modulates the simulated engine sound according to the driving history of the electric vehicle 10. change This is a "maturation mode" that allows the vehicle to develop a certain sound. On the other hand, the second mode simulates an engine sound according to the driving history of the electric vehicle 10. Do not change This is the "non-maturation mode." These first and second modes are switchable. For this purpose, the sound management system 100 shown in Figure 8 is further equipped with a mode switching unit 180.

[0064] In the first mode, the mode switching unit 180 instructs the sound source data management unit 120 to continue updating the basic sound source data 200. In the first mode, the sound source data management unit 120 provides the latest basic sound source data 200(N) to the engine sound generation unit 130. In the first mode, the engine sound generation unit 130 generates a simulated engine sound using the latest basic sound source data 200(N).

[0065] On the other hand, in the second mode, the mode switching unit 180 instructs the sound source data management unit 120 not to update the basic sound source data 200. In the second mode, the mode switching unit 180 may also instruct the operation history management unit 150 to stop updating the operation history information HST. In the second mode, the sound source data management unit 120 provides, for example, the initial state of the basic sound source data 200(0) to the engine sound generation unit 130. The engine sound generation unit 130 generates a pseudo-engine sound using the initial state of the basic sound source data 200(0).

[0066] The mode switching unit 180 may also be linked with the user interface 170. In that case, the user (driver) of the electric vehicle 10 can switch between the first mode and the second mode via the user interface 170 and the mode switching unit 180.

[0067] The system may use different modes for simulated engine sounds inside the vehicle and outside the vehicle. For example, speaker 70 includes an in-vehicle speaker that outputs sound inside the vehicle and an external speaker that outputs sound outside the vehicle. The sound management system 100 manages the simulated engine sound output from the in-vehicle speaker and the simulated engine sound output from the external speaker separately. For example, the simulated engine sound output from the in-vehicle speaker is generated by the first mode. This allows the driver to enjoy the refinement of the simulated engine sound. On the other hand, the simulated engine sound output from the external speaker is generated by the second mode. Since the second mode has a lower processing load than the first mode, the overall processing load is reduced.

[0068] Figure 9 is a block diagram showing yet another example of the functional configuration of the sound management system 100. In the example shown in Figure 9, a simulated engine sound that has been refined according to the driving history of one electric vehicle 10 is provided to another electric vehicle 10. For this purpose, the sound management system 100 further includes a sound source data distribution unit 190. The sound source data distribution unit 190 acquires one or more basic sound source data 200, including the latest basic sound source data 200(N), from the sound source data management unit 120. The sound source data distribution unit 190 then provides one or more basic sound source data 200, including the latest basic sound source data 200(N), to the other electric vehicle. The other electric vehicle plays a simulated engine sound based on the refined basic sound source data 200 that it has acquired. This allows the user of the other electric vehicle to immediately enjoy the refined simulated engine sound. The exchange of the refined simulated engine sound may be conducted on a paid basis. This allows the user of the providing electric vehicle 10 to profit.

[0069] Combinations of two or more of the examples shown in Figures 7 to 9 are also possible.

[0070] 2-3. Various Operational Patterns The following describes various operational modes of the sound management system 100 according to this embodiment.

[0071] Figure 10 is a block diagram illustrating the in-vehicle device 400 and management server 300 that constitute the sound management system 100. The in-vehicle device 400 and the management server 300 can communicate with each other via a communication network.

[0072] The in-vehicle device 400 is installed in the electric vehicle 10. The in-vehicle device 400 includes one or more processors 401 (hereinafter simply referred to as processor 401), one or more storage devices 402 (hereinafter simply referred to as storage devices 402), and a communication device 403. The processor 401 performs various processes. Examples of processors 401 include general-purpose processors, application-specific processors, CPUs, GPUs, ASICs, FPGAs, integrated circuits, conventional circuits, and / or combinations thereof. The processor 401 can also be called circuitry or processing circuitry. The storage devices 402 store (store) various information. Examples of storage devices 402 include volatile memory, non-volatile memory, HDDs, SSDs, etc. The communication device 403 communicates with the management server 300. The functions of the in-vehicle device 400 are realized through the cooperation of the processor 401 and the storage devices 402. Program 405 is a computer program executed by the processor 401. The functions of the in-vehicle device 400 may be realized through the cooperation of a processor 401 that executes program 405 and a storage device 402. Program 405 is stored in the storage device 402. Alternatively, program 405 may be recorded on a computer-readable recording medium.

[0073] The management server 300 includes one or more processors 301 (hereinafter simply referred to as processor 301), one or more storage devices 302 (hereinafter simply referred to as storage devices 302), and a communication device 303. The processor 301 performs various processes. Examples of processors 301 include general-purpose processors, application-specific processors, CPUs, GPUs, ASICs, FPGAs, integrated circuits, conventional circuits, and / or combinations thereof. The processor 301 can also be called circuitry or processing circuitry. The storage devices 302 store (store) various information. Examples of storage devices 302 include volatile memory, non-volatile memory, HDDs, SSDs, etc. The communication device 303 communicates with the in-vehicle devices 400 of a number of electric vehicles 10. The functions of the management server 300 are realized through the cooperation of the processor 301 and the storage devices 302. Program 305 is a computer program executed by the processor 301. The functions of the management server 300 may be realized through the cooperation of the processor 301, which executes program 305, and the storage device 302. Program 305 is stored in the storage device 302. Alternatively, program 305 may be recorded on a computer-readable recording medium.

[0074] Either the processor 401 of the in-vehicle device 400 or the processor 301 of the management server 300, or a combination thereof, corresponds to one or more processors 101 shown in Figure 1. Either the storage device 402 of the in-vehicle device 400 or the storage device 302 of the management server 300, or a combination thereof, corresponds to one or more storage devices 102 shown in Figure 1. Either the program 405 of the in-vehicle device 400 or the program 305 of the management server 300, or a combination thereof, corresponds to the sound management program 105 shown in Figure 1.

[0075] 2-3-1. Example 1 Figure 11 is a block diagram illustrating a first example of the operation mode of the sound management system 100. In this first example, the driving information acquisition unit 110, the sound source data management unit 120, the engine sound generation unit 130, the output unit 140, the driving history management unit 150, and the sound source adjustment unit 160 are all included in the in-vehicle device 400. The aging of the simulated engine sound is performed within the electric vehicle 10.

[0076] The sound source data distribution unit 190 is included in the management server 300. The sound source data distribution unit 190 of the management server 300 communicates with the in-vehicle device 400 of the electric vehicle 10 and acquires the basic sound source data 200 managed by the in-vehicle device 400. The sound source data distribution unit 190 then provides the acquired basic sound source data 200 to other electric vehicles.

[0077] 2-3-2. Second Example Figure 12 is a block diagram illustrating a second example of the operation of the sound management system 100. In this second example, compared to the first example described above, the driving history management unit 150 and the sound source adjustment unit 160 are included in the management server 300. The driving history management unit 150 centrally manages the driving history information HST (HST-1, HST-2, HST-3, ...) of multiple electric vehicles 10. For this purpose, the driving history information HST is associated with a vehicle ID. The driving history management unit 150 manages the driving history information HST for each vehicle ID.

[0078] The driving information acquisition unit 110 of the in-vehicle device 400 uploads a set of vehicle ID and driving information DRV to the management server 300. The upload frequency is arbitrary. The driving history management unit 150 of the management server 300 updates the driving history information HST associated with the vehicle ID based on the received driving information DRV.

[0079] Furthermore, the sound source adjustment unit 160 of the management server 300 generates adjustment information ADJ for the vehicle ID based on the driving history information HST. At this time, a sound source adjustment model 165 corresponding to the vehicle type specified by the user of the electric vehicle 10 is used. The sound source adjustment unit 160 then transmits the generated adjustment information ADJ for the vehicle ID to the electric vehicle 10 of that vehicle ID.

[0080] The sound source data management unit 120 of the electric vehicle 10 with the vehicle ID updates the basic sound source data 200 according to the adjustment information ADJ sent from the management server 300.

[0081] According to the second example, the processing load of the in-vehicle device 400 can be reduced. Furthermore, the storage capacity of the storage device 402 of the in-vehicle device 400 can be saved. In particular, since the amount of data for the driving history information HST tends to be large, the storage capacity of the storage device 402 of the in-vehicle device 400 can be effectively saved.

[0082] As a variation of the second example, the driving history management unit 150 may be included in the management server 300, and the sound source adjustment unit 160 may be included in the in-vehicle device 400. In this case, the sound source adjustment unit 160 of the in-vehicle device 400 obtains the driving history information HST associated with the vehicle ID from the driving history management unit 150 of the management server 300. The sound source adjustment unit 160 may generate adjustment information ADJ based on the driving history information HST, and then delete the driving history information HST.

[0083] 2-3-3. Third Example Figure 13 is a block diagram illustrating a third example of the operation of the sound management system 100. In this third example, compared to the first example described above, the sound source data management unit 120 is included in the management server 300. The sound source data management unit 120 centrally manages the basic sound source data 200 (200-1, 200-2, 200-3, ...) used in multiple electric vehicles 10. For this purpose, the basic sound source data 200 is associated with a vehicle ID. The sound source data management unit 120 manages the basic sound source data 200 for each vehicle ID.

[0084] The sound source adjustment unit 160 of the in-vehicle device 400 downloads the basic sound source data 200 associated with the vehicle ID from the management server 300. The sound source adjustment unit 160 updates the basic sound source data 200 based on the adjustment information ADJ. Then, the sound source adjustment unit 160 uploads the updated basic sound source data 200 and the vehicle ID set to the management server 300. The sound source data management unit 120 of the management server 300 stores the latest basic sound source data 200 associated with the vehicle ID.

[0085] In the third example, the basic sound source data 200 (200-1, 200-2, 200-3, ...) used in multiple electric vehicles 10 are centrally managed by the management server 300. This is preferable from the standpoint of managing and distributing the basic sound source data 200.

[0086] 2-3-4. The fourth example Figure 14 is a block diagram illustrating a fourth example of the operation mode of the sound management system 100. In the fourth example, compared to the first example above, the sound source data management unit 120, the operation history management unit 150, and the sound source adjustment unit 160 are included in the management server 300. The sound source data management unit 120 is the same as in the third example above. The operation history management unit 150 is the same as in the second example above.

[0087] The sound source adjustment unit 160 of the management server 300 generates adjustment information ADJ for the vehicle ID based on the driving history information HST. Furthermore, the sound source adjustment unit 160 updates the basic sound source data 200 associated with the vehicle ID based on the adjustment information ADJ. The sound source data management unit 120 of the management server 300 transmits the latest basic sound source data 200 associated with the vehicle ID to the electric vehicle 10 of that vehicle ID.

[0088] According to the fourth example, the processing load on the in-vehicle device 400 is minimized. Furthermore, the storage capacity of the storage device 402 of the in-vehicle device 400 is most efficiently utilized.

[0089] 2-4. Effects According to this embodiment, a simulated engine sound is output via a speaker 70 mounted in the electric vehicle 10. The simulated engine sound changes according to the driving history of the electric vehicle 10. This reproduces the aging (maturation) of the engine sound in an actual gasoline-powered vehicle according to its driving history. Therefore, it is possible to increase the satisfaction of drivers who seek greater realism.

[0090] 3. Application to electric vehicles equipped with manual mode (MT mode) The electric motors used as the power source in conventional electric vehicles (EVs) have significantly different torque characteristics compared to the internal combustion engines used as the power source in conventional vehicles (CVs). Due to these differences in torque characteristics, CVs require a transmission, whereas electric vehicles generally do not. Of course, conventional electric vehicles do not have a manual transmission (MT) that allows the driver to manually switch gear ratios. Therefore, there is a significant difference in driving feel between driving a conventional vehicle with an MT (hereinafter referred to as an MT vehicle) and driving an electric vehicle.

[0091] On the other hand, the torque of an electric motor can be controlled relatively easily by controlling the applied voltage and field. Therefore, with an electric motor, it is possible to obtain the desired torque characteristics within the motor's operating range by implementing appropriate control. Taking advantage of this characteristic, the torque of an electric vehicle can be controlled to simulate the torque characteristics unique to a manual transmission (MT) vehicle. Furthermore, a simulated shifter can be installed in an electric vehicle to allow the driver to experience a driving sensation similar to that of an MT vehicle. In this way, it becomes possible to simulate an MT vehicle in an electric vehicle.

[0092] In other words, the electric vehicle controls the output of the electric motor to simulate the driving characteristics (torque characteristics) unique to a manual transmission (MT) vehicle. The driver operates a simulated shifter to perform a simulated manual gear change. In response to the driver's simulated manual gear change, the electric vehicle changes its driving characteristics (torque characteristics) to simulate an MT vehicle. As a result, the driver of the electric vehicle can get the feeling that they are driving an MT vehicle. The electric motor control mode used to simulate the driving characteristics and manual gear change operation of an MT vehicle will be referred to as "manual mode" or "MT mode" below.

[0093] The electric vehicle 10 according to this disclosure may be equipped with such a manual mode (MT mode). In MT mode, the electric vehicle 10 generates a simulated engine sound in response to the driver's driving operations and outputs the simulated engine sound through the speaker 70. Not only the driving operations of an MT vehicle but also the engine sound of an MT vehicle are reproduced, thus increasing the satisfaction of drivers seeking realism. Furthermore, as described above, even the aging (maturation) of the engine sound in an MT vehicle is reproduced, further increasing the satisfaction of drivers seeking realism.

[0094] The following describes an example configuration of an electric vehicle 10 equipped with a manual mode (MT mode).

[0095] 3-1. First Configuration Example (Sequential Shifter) Figure 15 is a block diagram showing a first configuration example of the power control system of an electric vehicle 10 according to this embodiment. The electric vehicle 10 is equipped with an electric motor 44, a battery 46, and an inverter 42. The electric motor 44 is a power device for driving. The battery 46 stores electrical energy to drive the electric motor 44. In other words, the electric vehicle 10 is a battery electric vehicle (BEV) that runs on the electrical energy stored in the battery 46. The inverter 42 converts the DC power input from the battery 46 during acceleration into driving power for the electric motor 44. The inverter 42 also converts the regenerative power input from the electric motor 44 during deceleration into DC power and charges the battery 46.

[0096] The electric vehicle 10 is equipped with an accelerator pedal 22 for the driver to input an acceleration request to the electric vehicle 10. The accelerator pedal 22 is equipped with an accelerator position sensor 32 for detecting the accelerator opening degree.

[0097] The electric vehicle 10 is equipped with a sequential shifter 24. The sequential shifter 24 may be a paddle-type shifter or a lever-type pseudo-shifter.

[0098] The paddle shifters are dummies and not genuine paddle shifters. They have a structure similar to the paddle shifters found on clutchless manual transmission vehicles. The paddle shifters are mounted on the steering wheel. They feature an upshift switch and a downshift switch to determine the operating position. The upshift switch emits an upshift signal 34u when pulled towards the user, and the downshift switch emits a downshift signal 34d when pulled towards the user.

[0099] On the other hand, the lever-type dummy shifter, like the paddle-type shifter, is a dummy that is different from the actual shifter. The lever-type dummy shifter has a structure that resembles the lever-type shifter found in clutchless manual transmission vehicles. The lever-type dummy shifter is configured to output an upshift signal 34u when the shift lever is moved forward, and a downshift signal 34d when the shift lever is moved backward.

[0100] Wheel speed sensors 36 are provided on the wheels 26 of the electric vehicle 10. The wheel speed sensors 36 are used as vehicle speed sensors to detect the vehicle speed of the electric vehicle 10. In addition, a rotational speed sensor 38 is provided on the electric motor 44 to detect its rotational speed.

[0101] The electric vehicle 10 is equipped with a control device 50. The control device 50 is typically an electronic control unit (ECU) installed in the electric vehicle 10. The control device 50 may be a combination of multiple ECUs. The control device 50 comprises 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 and various data related to programs that can be executed by the processor. The program consists of multiple instructions. The processor reads and executes the program and data from memory and generates control signals based on signals obtained from each sensor.

[0102] For example, the control device 50 controls the electric motor 44 by PWM control of the inverter 42. The control device 50 receives signals from the accelerator position sensor 32, the sequential shifter 24 (upshift switch and downshift switch if the sequential shifter 24 is a paddle-type shifter), the wheel speed sensor 36, and the rotational speed sensor 38. The control device 50 processes these signals and calculates a motor torque command value for PWM control of the inverter 42.

[0103] The control device 50 includes an automatic mode (EV mode) and a manual mode (MT 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 in response to the operation of the accelerator pedal 22. On the other hand, the manual mode is a control mode for driving the electric vehicle 10 like a manual transmission vehicle. The manual mode is programmed to change the output characteristics of the electric motor 44 in response to the operation of the accelerator pedal 22 in response to upshift and downshift operations on the sequential shifter 24. In other words, the manual mode is a control mode that can change the output of the electric motor 44 in response to driving operations of vehicle components other than the accelerator pedal 22 and brake pedal. The automatic mode (EV mode) and the manual mode (MT mode) are switchable.

[0104] 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 may be an independent ECU, or it may be an ECU function obtained by executing a program stored in memory on a processor.

[0105] The automatic mode torque calculation unit 54 has a function to calculate the motor torque when the electric motor 44 is controlled in automatic mode. The automatic mode torque calculation unit 54 stores a motor torque command map. 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. 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 sequential shifter 24, that operation is not reflected in the motor torque.

[0106] The manual mode torque calculation unit 56 includes an MT vehicle model. The MT vehicle model is a model for calculating the drive wheel torque that should be obtained by operating the accelerator pedal 22 and the sequential shifter 24, assuming that the electric vehicle 10 is an MT vehicle.

[0107] The MT vehicle model provided by the manual mode torque calculation unit 56 will be described with reference to Figure 16. As shown in Figure 16, the MT vehicle model includes an engine model 561, a clutch model 562, and a transmission model 563. The engine, clutch, and transmission virtually realized by the MT vehicle model are referred to as the virtual engine, virtual clutch, and virtual transmission, respectively. The engine model 561 models the virtual engine. The clutch model 562 models the virtual clutch. The transmission model 563 models the virtual transmission.

[0108] Engine model 561 calculates the virtual engine speed Ne and virtual engine output torque Teout. The virtual engine speed Ne is calculated based on the wheel rotation speed Nw, the overall reduction ratio R, and the virtual clutch slip ratio Rslip. For example, the virtual engine speed Ne is expressed by equation (1) below. Equation (1): Ne = Nw × R / (1 - Rslip)

[0109] The virtual engine output torque Teout is calculated from the virtual engine rotational speed Ne and the accelerator pedal opening Pap. As shown in Figure 16, a map defining the relationship between the accelerator pedal opening Pap, the virtual engine rotational speed Ne, and the virtual engine output torque Teout is used to calculate the virtual engine output torque Teout. This map provides the virtual engine output torque Teout for each accelerator pedal opening Pap relative to the virtual engine rotational speed Ne. The torque characteristics shown in Figure 16 can be set to simulate a gasoline engine, a diesel engine, a naturally aspirated engine, or a turbocharged engine.

[0110] The clutch model 562 calculates the torque transmission gain k. The torque transmission gain k is a gain used to calculate 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 temporarily opens 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 Figure 16. In this map, the torque transmission gain k is given for the virtual clutch opening Pc. In Figure 16, 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 range from Pc0 to Pc1 and the range from Pc2 to Pc3 are dead zones where the torque transmission gain k does not change with respect to the virtual clutch opening Pc. The clutch model 562 uses the torque transmission 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).

[0111] Furthermore, 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. Similar to the torque transmission gain k, a map can be used to calculate the slip ratio Rslip, where the slip ratio Rslip is given to the virtual clutch opening Pc.

[0112] The transmission model 563 calculates the gear ratio r. The gear ratio r is the gear ratio determined by the virtual gear stage GP in the virtual transmission. The virtual gear stage GP is increased by one step when the sequential shifter 24 is upshifted. Conversely, the virtual gear stage GP is decreased by one step when the sequential shifter 24 is downshifted. The transmission model 563 has a map as shown in Figure 16. In this map, the gear ratio r is assigned to the virtual gear stage GP such that the larger the virtual gear stage GP, the smaller the gear ratio r becomes. 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 according to the gear ratio r switching. This discontinuous change in transmission output torque Tgout creates a shift shock, giving the vehicle the feel of having a stepped transmission.

[0113] The MT 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 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).

[0114] The control device 50 converts the drive wheel torque Tw calculated in the MT vehicle model into a required motor torque Tm. The required motor torque Tm is the motor torque required to achieve the drive wheel torque Tw calculated in the MT vehicle model. The reduction ratio from the output shaft of the electric motor 44 to the drive wheels is used to convert the drive wheel torque Tw into a required motor torque Tm. The control device 50 then controls the inverter 42 to control the electric motor 44 according to the required motor torque Tm.

[0115] Figure 17 shows a comparison of the torque characteristics of an electric motor 44 realized by motor control using an MT vehicle model with the torque characteristics of an electric motor 44 realized by normal motor control as an electric vehicle (EV). As shown in Figure 17, motor control using an MT vehicle model can realize torque characteristics (solid line in the figure) that simulate the torque characteristics of an MT vehicle, depending on the virtual gear stage set by the sequential shifter 24. Note that in Figure 17, the number of gear stages is set to 6.

[0116] 4-2. Second Configuration Example Figure 18 is a block diagram showing a second configuration example of the power control system of the electric vehicle 10 according to this embodiment. Here, only the configurations that differ from the first configuration example described above will be explained. Specifically, in the second configuration example, the electric vehicle 10 is equipped with a pseudo-shift lever (pseudo-shift device) 27 and a pseudo-clutch pedal 28 instead of the sequential shifter 24 provided in the first configuration example. The pseudo-shift lever 27 and pseudo-clutch pedal 28 are merely dummies and are different from the actual shift lever and clutch pedal.

[0117] The simulated shift lever 27 has a structure that mimics the shift lever found in a manual transmission (MT) vehicle. The placement and feel of the simulated shift lever 27 are equivalent to those of an actual MT vehicle. The simulated shift lever 27 has positions corresponding to each gear, such as 1st, 2nd, 3rd, 4th, 5th, 6th, reverse, and neutral. The simulated shift lever 27 is equipped with a shift position sensor 27a that detects the gear by determining which position the simulated shift lever 27 is in.

[0118] The simulated clutch pedal 28 has a structure that simulates the clutch pedal found in a manual transmission (MT) vehicle. The placement and feel of the simulated clutch pedal 28 are equivalent to those of an actual MT vehicle. The simulated clutch pedal 28 is operated when the simulated shift lever 27 is operated. In other words, the driver depresses the simulated clutch pedal 28 when they want to change the gear setting using the simulated shift lever 27, and releases the pedal when the gear setting change is complete, returning the simulated clutch pedal 28 to its original position. The simulated clutch pedal 28 is equipped with a clutch position sensor 28a for detecting the amount the simulated clutch pedal 28 is depressed.

[0119] The control device 50 receives 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. The control device 50 processes these signals and calculates a motor torque command value for PWM control of the inverter 42.

[0120] The control device 50, similar to the first configuration example described above, 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 in response to the operation of the accelerator pedal 22. On the other hand, the manual mode is a control mode for driving the electric vehicle 10 like a manual transmission vehicle. The manual mode is programmed to change the output and output characteristics of the electric motor 44 in response to the operation of the accelerator pedal 22 in response to the operation of the simulated clutch pedal 28 and the simulated shift lever (simulated shift device) 27. In other words, the manual mode is a control mode that can change the output of the electric motor 44 in response to driving operations of vehicle components other than the accelerator pedal 22 or brake pedal.

[0121] The vehicle model provided by the manual mode torque calculation unit 56 is the same as that shown in Figure 16. However, the virtual clutch opening Pc is replaced by the amount of depression of the pseudo clutch pedal 28 detected by the clutch position sensor 28a. In addition, 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 Symbols]

[0122] 10…Electric vehicle, 11…Sensor, 44…Electric motor, 70…Speaker, 100…Sound management system, 110…Driving information acquisition unit, 120…Sound source data management unit, 130…Engine sound generation unit, 140…Output unit, 150…Driving history management unit, 160…Sound source adjustment unit, 165…Sound source adjustment model, 170…User interface, 180…Mode switching unit, 190…Sound source data distribution unit, 200…Basic sound source data, 300…Management server, 400…In-vehicle device, DRV…Driving information, ES…Engine sound data, HST…Driving history information

Claims

1. A sound management system applicable to an electric vehicle that uses an electric motor as a power source for driving, The system comprises one or more processors configured to generate a simulated engine sound and output the simulated engine sound through a speaker mounted on the electric vehicle, The one or more processors described above are configured to acquire driving history information indicating the driving history of the electric vehicle and to change the simulated engine sound according to the driving history. The one or more processors are configured to generate the simulated engine sound in order to reproduce the changes in engine sound over time according to the driving history of the engine vehicle. Sound management system.

2. A sound management system according to claim 1, The one or more processors are configured to acquire the virtual engine rotational speed assuming that the electric vehicle is driven by a virtual engine. The driving history of the electric vehicle includes the history of the virtual engine speed. Sound management system.

3. A sound management system according to claim 1, The driving history of the electric vehicle includes at least one of the following: total driving time, total driving distance, longitudinal acceleration history, lateral acceleration history, vehicle tilt history, and altitude history. Sound management system.

4. A sound management system according to claim 1, The device further comprises one or more storage devices for storing basic sound source data for generating the aforementioned simulated engine sound, The one or more processors are further configured to update the basic sound source data used to generate the simulated engine sound according to the driving history. Sound management system.

5. A sound management system according to claim 4, The one or more storage devices store both the initial state of the basic sound source data and the latest state of the basic sound source data. Sound management system.

6. A sound management system according to claim 4, The one or more storage devices store only the latest basic sound source data. Sound management system.

7. A sound management system applicable to an electric vehicle that uses an electric motor as a power source for driving, One or more processors configured to generate a simulated engine sound and output the simulated engine sound through a speaker mounted on the electric vehicle, One or more storage devices that store basic sound source data for generating the aforementioned pseudo-engine sound, Equipped with, The one or more processors described above are configured to acquire driving history information indicating the driving history of the electric vehicle and to change the simulated engine sound according to the driving history. The one or more processors are further configured to update the basic sound source data used to generate the simulated engine sound according to the driving history. The aforementioned one or more storage devices store multiple types of basic sound source data at multiple timings, The one or more processors are configured to select one of the multiple types of basic sound source data specified by the user, and to generate the pseudo-engine sound based on the selected basic sound source data. Sound management system.

8. A sound management system applicable to an electric vehicle that uses an electric motor as a power source for driving, One or more processors configured to generate a simulated engine sound and output the simulated engine sound through a speaker mounted on the electric vehicle, One or more storage devices that store basic sound source data for generating the aforementioned pseudo-engine sound, Equipped with, The one or more processors described above are configured to acquire driving history information indicating the driving history of the electric vehicle and to change the simulated engine sound according to the driving history. The one or more processors are further configured to update the basic sound source data used to generate the simulated engine sound according to the driving history. The one or more processors are further configured to provide the updated basic sound source data, which is determined according to the driving history of the electric vehicle, to other electric vehicles. Sound management system.

9. A sound management system according to any one of claims 1 to 8, The aforementioned electric vehicle is equipped with an accelerator pedal and a sequential shifter, In manual mode, the electric vehicle is configured to change the output characteristics of the electric motor in response to the operation of the accelerator pedal in accordance with the shift operation of the sequential shifter. Sound management system.

10. A sound management system according to any one of claims 1 to 8, The electric vehicle is equipped with an accelerator pedal, a simulated clutch pedal, and a simulated shift device. The aforementioned simulated clutch pedal is operated when the simulated shift device is operated. In manual mode, the electric vehicle is configured to change the output of the electric motor in response to the operation of the accelerator pedal in accordance with the operation of the simulated clutch pedal and the operation of the simulated shift device. Sound management system.

11. An electric vehicle that uses an electric motor as a power source for driving, The system comprises one or more processors configured to generate a simulated engine sound and output the simulated engine sound through a speaker mounted on the electric vehicle, The one or more processors described above are configured to acquire driving history information indicating the driving history of the electric vehicle and to change the simulated engine sound according to the driving history. The one or more processors are configured to generate the simulated engine sound in order to reproduce the changes in engine sound over time according to the driving history of the engine vehicle. Electric vehicle.

12. A sound management program applicable to electric vehicles that use an electric motor as a power source for driving, The aforementioned sound management program, when executed by a computer, performs engine sound output processing. The aforementioned engine sound output processing is performed by A process that generates a simulated engine sound and outputs the simulated engine sound through a speaker installed in the electric vehicle, The process involves acquiring driving history information showing the driving history of the electric vehicle, and changing the simulated engine sound according to the driving history. Includes, The process of changing the simulated engine sound according to the aforementioned driving history includes generating the simulated engine sound in a way that reproduces the changes in engine sound over time in a gasoline-powered vehicle according to the aforementioned driving history. Sound management program.

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