Vehicle

Abstract

To provide a vehicle that suppresses feeling of discomfort caused by not getting expected sound change when a transmission is operated, even if a user of the vehicle is the user accustomed to conventional manual transmission engine vehicles.SOLUTION: A vehicle 100 is provided with: a transmission (transfer case) 8, which is provided between a power source (electric motor 6) and drive wheels (rear wheels 18, front wheels 26) and being able for a user to switch transmission ratios manually; and a sound generator (amplifier 30, speaker 32, sound control unit 120) to generate artificial sound when the vehicle travels. The sound generator performs at least one of the following: the higher a gear ratio of the transmission, the higher the frequency of the sound, and the higher the gear ratio of the transmission, the higher the sound pressure of the sound.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a vehicle equipped with a power source that is quieter than an internal combustion engine and a transmission that allows a user to manually change the gear ratio. [Background technology]

[0002] JP 2022-030862 A discloses a conventional technology related to an electric vehicle that can simulate the manual shifting operation of a vehicle equipped with a manual transmission powered by an internal combustion engine (hereinafter referred to as a manual shift engine vehicle) by controlling an electric motor. The electric vehicle according to the conventional technology is equipped with a pseudo shift lever, and outputs a torque corresponding to the shift position of the pseudo shift lever and the accelerator opening to the electric motor. In addition, the electric vehicle according to the conventional technology calculates a virtual engine rotation speed based on the shift position of the pseudo shift lever and the accelerator opening, and generates an engine sound corresponding to the virtual engine rotation speed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-030862 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, the combination of an actual manual transmission with an electric vehicle is also being considered. The rotation speed of the electric motor changes when the gear ratio is changed by shifting the manual transmission. However, although the sound generated by the electric motor changes with the change in rotation speed, the change is much smaller than the change in sound generated by an internal combustion engine. For this reason, users, especially those who are accustomed to conventional manual transmission engine vehicles, may feel uncomfortable with the difference between the change in sound expected from the shift operation and the change in the actual sound generated by the power source.

[0005] The present disclosure has been made in consideration of the above problems. One objective of the present disclosure is to provide a vehicle that can reduce the discomfort felt by users who are accustomed to conventional manual transmission engine vehicles due to the lack of an expected change in sound when operating the transmission. [Means for solving the problem]

[0006] The present disclosure provides a vehicle for achieving the above object. According to a first aspect of the present disclosure, the vehicle includes a transmission. The transmission is a manual transmission that allows a user to manually switch the gear ratio, and is provided between a power source and a driving wheel. The power source of the vehicle may be a quieter power source than an internal combustion engine, for example, an electric motor. According to the first aspect, the vehicle includes a sound generator that artificially generates a sound while the vehicle is traveling. The sound generator increases the frequency of the generated sound as the gear ratio of the transmission increases, or increases the sound pressure of the generated sound as the gear ratio of the transmission increases. Alternatively, the sound generator increases the frequency of the generated sound and the sound pressure of the generated sound as the gear ratio of the transmission increases. Furthermore, the sound generator may increase the frequency of the generated sound as the vehicle speed of the vehicle increases, or may increase the sound pressure of the generated sound as the vehicle speed of the vehicle increases. Alternatively, the sound generator may generate a higher frequency of the sound and increase the sound pressure of the sound as the vehicle speed of the vehicle increases. Also, the sound generator may generate a higher frequency of the sound and increase the sound pressure of the sound as the accelerator pedal depression increases. Alternatively, the sound generator may generate a higher frequency of the sound and increase the sound pressure of the sound as the accelerator pedal depression increases.

[0007] According to a second aspect of the present disclosure, the power source may be an electric motor, and the vehicle may further include a pseudo shifter capable of selecting a plurality of virtual shift positions. Also, according to the second aspect, the sound generator may generate a higher frequency of sound the lower the virtual shift position selected by the pseudo shifter, or may generate a higher sound pressure of sound the lower the virtual shift position selected by the pseudo shifter. Alternatively, the sound generator may generate a higher frequency of sound and generate a higher sound pressure of sound the lower the virtual shift position selected by the pseudo shifter. Furthermore, according to the second aspect, the vehicle may include a motor control device that changes the torque of an electric motor as a power source according to the virtual shift position selected by the pseudo shifter, the vehicle speed of the host vehicle, and the accelerator opening. The motor control device may increase the torque of the electric motor at the same vehicle speed and the same accelerator opening the lower the selected virtual shift position, and may limit the vehicle speed range in which the virtual shift position can be selected to a lower speed side.

[0008] According to a third aspect of the present disclosure, the power source may be an electric motor, and the vehicle may include a pseudo clutch operating tool that can be operated against a reaction force from a start position to a terminal position. Also, according to the third aspect, the sound generator may temporarily lower the frequency of the sound generated or temporarily reduce the sound pressure of the sound generated while the pseudo clutch operating tool is returned from the terminal position to the start position. Alternatively, the sound generator may temporarily lower the frequency of the sound generated and temporarily reduce the sound pressure of the sound generated while the pseudo clutch operating tool is returned from the terminal position to the start position. Furthermore, according to the third aspect, the vehicle may include a motor control device that changes the torque of the motor as the power source in accordance with the operation amount of the pseudo clutch operating tool, the vehicle speed of the host vehicle, and the accelerator opening. The motor control device may reduce the torque of the electric motor when the pseudo clutch operating tool is in the terminal position, and generate the torque of the electric motor on the way until the pseudo clutch operating tool is returned from the terminal position to the start position. Effect of the Invention

[0009] According to the vehicle of the present disclosure, when the driver, who is the user, operates the transmission, at least one of the sound pressure and frequency of the sound generated from the sound generator changes according to the change in the gear ratio that accompanies the operation. The change in sound becomes higher in sound pressure or frequency as the gear ratio of the transmission increases, and is similar to the change in engine sound that accompanies a shift operation that occurs in a conventional manual transmission engine vehicle. Therefore, even if the user of the vehicle is a user who is accustomed to conventional manual transmission engine vehicles, the feeling of discomfort caused by not obtaining the expected change in sound when operating the transmission is suppressed. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a configuration of a vehicle according to a first embodiment of the present disclosure. [Diagram 2] FIG. 4 is a diagram showing an example of a sound pressure map according to the first embodiment of the present disclosure. [Diagram 3] FIG. 11 is a diagram showing another example of a sound pressure map according to the first embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram showing a flow of sound pressure control according to the first embodiment of the present disclosure. [Diagram 5] FIG. 11 is a diagram showing a modified example of the vehicle according to the first embodiment of the present disclosure. [Figure 6] FIG. 4 is a diagram showing a configuration of a vehicle according to a second embodiment of the present disclosure. [Figure 7] FIG. 11 is a diagram illustrating an example of a vehicle model according to a second embodiment of the present disclosure. [Figure 8] FIG. 11 is a diagram showing an example of a sound pressure map according to a second embodiment of the present disclosure. [Figure 9] FIG. 11 is a diagram showing a flow of sound pressure control according to a second embodiment of the present disclosure. [Figure 10] FIG. 13 is a diagram showing a configuration of a vehicle according to a third embodiment of the present disclosure. [Figure 11] FIG. 13 is a diagram illustrating an example of a vehicle model according to a third embodiment of the present disclosure. [Figure 12] FIG. 13 is a diagram illustrating an example of a sound pressure map according to a third embodiment of the present disclosure. [Figure 13]FIG. 11 is a diagram showing a flow of sound pressure control according to a third embodiment of the present disclosure. [Figure 14] FIG. 13 is a diagram showing an example of a change in sound pressure due to sound pressure control according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] 1. First embodiment 1-1.Vehicle power system configuration 1 is a diagram showing a schematic configuration of a vehicle 100 according to a first embodiment. First, the configuration of the power system of the vehicle 100 will be described with reference to FIG.

[0012] The vehicle 100 is equipped with an electric motor (M) 6 as a power source for traveling. The vehicle 100 also has a battery (BATT) 2 and an inverter (INV) 4. The battery 2 stores electric energy for driving the electric motor 6. In other words, the vehicle 100 is a battery electric vehicle (BEV) that runs on the electric energy stored in the battery 2. The electric motor 6 is, for example, a three-phase AC motor. The inverter 4 is, for example, a voltage type inverter, and controls the torque of the electric motor 6 by PWM control.

[0013] The vehicle 100 is equipped with a transfer case (T / C) 8. An output shaft of an electric motor 6 is connected to the transfer case 8. The transfer case 8 is connected to a rear differential gear 14 by a rear propeller shaft 12. The rear differential gear 14 is connected to left and right rear wheels 18 by left and right rear drive shafts 16. The transfer case 8 is also connected to a front differential gear 22 by a front propeller shaft 20. The front differential gear 22 is connected to left and right front wheels 26 by left and right front drive shafts 24.

[0014] The transfer case 8 is a device that switches between two-wheel drive and four-wheel drive. The transfer case 8 is connected to a shift device 10 provided in the vehicle cabin. The shift device 10 is equipped with a lever (not shown). The driver operates the lever of the shift device 10 to mechanically switch between two-wheel drive and four-wheel drive. When four-wheel drive is selected, the driving force of the electric motor 6 is distributed to the rear propeller shaft 12 and the front propeller shaft 20 in the transfer case 8, and the driving force is transmitted to the rear wheels 18 and the front wheels 26. When two-wheel drive is selected, the front propeller shaft 20 is disconnected from the power transmission path in the transfer case 8, and the driving force of the electric motor 6 is transmitted only to the rear wheels 18.

[0015] The transfer case 8 is equipped with a transmission mechanism for switching between a high-speed gear and a low-speed gear. The high-speed gear is a gear with a small gear ratio, and the low-speed gear is a gear with a large gear ratio. Switching between the high-speed gear and the low-speed gear can be performed when four-wheel drive is selected. When two-wheel drive is selected, the high-speed gear is used. When four-wheel drive is selected, switching between the high-speed gear and the low-speed gear is performed mechanically by the driver operating the lever of the shift device 10. By operating the lever of the shift device 10, the driver can switch between two-wheel drive in high gear and four-wheel drive in high gear, and between four-wheel drive in high gear and four-wheel drive in low gear via neutral.

[0016] 1-2. Vehicle control system configuration Next, the configuration of the control system of the vehicle 100 will be described with reference to FIG.

[0017] The vehicle 100 is equipped with a vehicle speed sensor 40. At least one of wheel speed sensors (not shown) provided on each of the left and right front wheels 26 and the left and right rear wheels 18 is used as the vehicle speed sensor 40. The vehicle 100 is also equipped with an accelerator position sensor 42. The accelerator position sensor 42 is provided on an accelerator pedal (not shown) and outputs a signal indicating the depression amount of the accelerator pedal, i.e., the accelerator opening degree. The vehicle 100 is also equipped with a gear stage sensor 44. The gear stage sensor 44 is provided on the shift device 10 and outputs a signal indicating the gear stage of the transfer case 8 selected by lever operation. Hereinafter, the gear stage that realizes two-wheel drive in high gear is represented as H2, the gear stage that realizes four-wheel drive in high gear is represented as H4, the gear stage that realizes four-wheel drive in low gear is represented as L4, and neutral is represented as N.

[0018] The vehicle 100 includes a control device 101. Sensors and devices to be controlled mounted on the vehicle 100 are connected to the control device 101 via an in-vehicle network. The vehicle speed sensor 40, the accelerator position sensor 42, and the gear stage sensor 44 are examples of sensors mounted on the vehicle 100. The control device 101 is typically an electronic control unit (ECU). The control device 101 may be a combination of multiple ECUs. The control device 101 includes an interface, a memory, and a processor (not shown). The interface is connected to the in-vehicle network. The memory includes a RAM for temporarily recording data, and a ROM for storing programs executable by the processor and various data related to the programs. The programs are composed of multiple instructions. The processor reads out and executes the programs and data from the memory, and generates control signals based on signals acquired from each sensor. The control device 101 may include one or more processors.

[0019] The control device 101 includes a motor control device 110 and a sound control device 120. In detail, a program stored in a memory is executed by a processor, so that the processor functions as at least the motor control device 110 and the sound control device 120. The processor functioning as the motor control device 110 and the processor functioning as the sound control device 120 may be separate processors or may be the same processor.

[0020] The control target of the motor control device 110 is the inverter 4. The motor control device 110 receives the vehicle speed obtained from the signal of the vehicle speed sensor 40 and the accelerator opening obtained from the signal of the accelerator position sensor 42. The motor control device 110 executes process P111 based on the vehicle speed and the accelerator opening. In process P111, the torque to be generated in the electric motor 6 is calculated. The motor control device 110 has a motor torque map with the accelerator opening and the vehicle speed as parameters. The motor control device 110 inputs the vehicle speed and the accelerator opening to the motor torque map, and controls the inverter 4 so that the electric motor 6 generates the torque obtained from the motor torque map.

[0021] The object of control of the sound control device 120 is the amplifier 30. The amplifier 30 changes the sound pressure of the speaker 32 installed in the passenger compartment of the vehicle 100. An artificially generated sound is output from the speaker 32. The sound control device 120 can generate various sounds. One of the artificial sounds is a simulated engine sound that imitates the engine sound of a conventional engine vehicle. The sound control device 120 changes the sound pressure of the simulated engine sound generated from the speaker 32 by controlling the amplifier 30. The sound control device 120, together with the speaker 32 and the amplifier 30, constitutes a sound generator.

[0022] The gear stage of the transfer case 8 obtained from the signal of the gear stage sensor 44 is input to the sound control device 120. The sound control device 120 executes process P121 based on the gear stage. In process P121, a sound pressure map to be used for controlling the amplifier 30 is selected. The sound pressure maps include a map for a low gear and a map for a high gear. The map for a low gear is a map selected when the gear stage is L4. The map for a high gear is a map selected when the gear stage is H4 and when the gear stage is H2. The sound control device 120 selects a sound pressure map according to the current gear stage of the transfer case 8.

[0023] The sound control device 120 also receives the vehicle speed obtained from the signal of the vehicle speed sensor 40 and the accelerator opening obtained from the signal of the accelerator position sensor 42. Using the sound pressure map selected in process P121, the sound control device 120 executes process P122 based on the vehicle speed and the accelerator opening. In process P122, the sound pressure according to the vehicle speed and the accelerator opening is calculated using the sound pressure map. The sound control device 120 controls the amplifier 30 to realize the sound pressure calculated in process P122.

[0024] FIG. 2 is a diagram showing an example of a sound pressure map according to the first embodiment. In the sound pressure map M01, sound pressure data is set relative to the vehicle speed so that the sound pressure increases as the vehicle speed increases. The difference between the map M11 for low gear and the map M12 for high gear is the magnitude of the sound pressure for the same vehicle speed. When compared at the same vehicle speed, both maps M11 and M12 are created so that the sound pressure in the map M11 for low gear is higher and the sound pressure in the map M12 for high gear is lower. In process P122, the sound pressure is calculated from the vehicle speed using the sound pressure map selected in process P121 from the map M11 for low gear and the map M12 for high gear.

[0025] The accelerator opening is used to calculate the sound pressure when no vehicle speed is generated. In conventional engine vehicles, there is a time lag between when the accelerator pedal is depressed and when the vehicle speed is generated. However, engine sound is generated during this time lag. On the other hand, when the vehicle is stopped with the accelerator pedal not depressed, no engine sound is generated or only a slight idling sound is generated. Therefore, in process P121, the sound pressure when no vehicle speed is generated is calculated based on the idling opening. In the map M11 for low gear and the map M12 for high gear, the sound pressure when the accelerator opening is on is set for the vehicle speed.

[0026] The sound pressure map is not limited to the example shown in FIG. 2. The sound pressure map may be created so that the sound pressure calculated in the map for low gear is larger than the sound pressure calculated in the map for high gear when compared at the same vehicle speed. The sound pressure map M01A shown in FIG. 3 is another example of a sound pressure map that can be used in the sound control device 120. As shown by the dashed line in FIG. 3, when the vehicle speed exceeds the threshold speed, the increase rate of the sound pressure with respect to the increase in the vehicle speed may be reduced. Alternatively, as shown by the dashed line in FIG. 3, when the vehicle speed exceeds the threshold speed, the sound pressure may be maintained at a constant value regardless of the increase in the vehicle speed. The threshold speed v1 in the map M11 for low gear may be the same as the threshold speed v2 in the map M12 for high gear, or may be lower. According to the setting of the sound pressure map shown in FIG. 3, it is possible to prevent the sound pressure from becoming excessive for the occupant in the high speed range.

[0027] 1-3. Sound pressure control 4 is a diagram showing the flow of sound pressure control executed by the control device 101 in the vehicle 100. First, in step S101, the gear position of the transfer case 8 is identified. If the gear position is L4, the flow proceeds to step S102, where sound pressure data corresponding to the vehicle speed is obtained from the map for low gears. If the gear position is H4 or H2, the flow proceeds to step S103, where sound pressure data corresponding to the vehicle speed is obtained from the map for high gears. Then, in step S104, a simulated engine sound is generated from the speaker 32 in accordance with the sound pressure data obtained in step S102 or step S103.

[0028] When the gear stage of the transfer case 8 is shifted from H4 to L4, the sound pressure map is switched from the map for high-speed gears to the map for low-speed gears, and the sound pressure of the engine sound emitted from the speaker 32 is increased. Conversely, when the gear stage is shifted from L4 to H4, the sound pressure map is switched from the map for low-speed gears to the map for high-speed gears, and the sound pressure of the simulated engine sound emitted from the speaker 32 is reduced. The fact that the sound pressure of the simulated engine sound increases as the gear ratio increases and decreases as the gear ratio decreases is similar to the change in engine sound accompanying the shift operation that occurs in a conventional manual transmission engine vehicle. Therefore, by changing the sound pressure of the simulated engine sound according to the driver's gear shift operation by the above-mentioned sound pressure control, it is possible to meet the expectations of the driver, especially a driver who is accustomed to a conventional manual transmission engine vehicle.

[0029] 1-4.Modifications Next, a modified example of the vehicle according to the present embodiment will be described with reference to Fig. 5. In the modified example, the amplifier 30 shown in Fig. 1 is replaced with a frequency modulator (FMC) 31 shown in Fig. 5, and the sound control device 120 shown in Fig. 1 is replaced with a sound control device 130 shown in Fig. 5.

[0030] The object of control of the sound control device 130 is the frequency modulator 31. The frequency modulator 31 changes the frequency of the simulated engine sound emitted from the speaker 32. The sound control device 130 changes the frequency of the simulated engine sound generated from the speaker 32 by controlling the frequency modulator 31. In a modified example, the sound control device 130, together with the speaker 32 and the frequency modulator 31, constitutes a sound generator.

[0031] The gear position of the transfer case 8 is input to the sound control device 130. The sound control device 130 executes a process P131 based on the gear position. In the process P131, a frequency map M011 used to control the amplifier 30 is selected. The frequency map M011 includes a map M111 for low gear and a map M112 for high gear. The map M111 for low gear is a map selected when the gear position is L4. The map M112 for high gear is a map selected when the gear position is H4 and when the gear position is H2. In the frequency map M011, frequency data is set for a vehicle speed so that the frequency increases as the vehicle speed increases. The difference between the map M111 for low gear and the map M112 for high gear is the height of the frequency for the same vehicle speed. When compared at the same vehicle speed, both maps M111 and M112 are created so that the frequency of the map M111 for low gear is higher and the frequency of the map M112 for high gear is lower. The sound control device 130 selects the frequency map M011 according to the current gear stage of the transfer case 8.

[0032] The sound control device 130 also receives inputs of the vehicle speed and the accelerator opening. The sound control device 130 executes process P132 based on the vehicle speed and the accelerator opening using the frequency map M011 selected in process P131. In process P132, a frequency according to the vehicle speed and the accelerator opening is calculated using the frequency map. As in the case of the sound pressure map, the accelerator opening is used to calculate the frequency when the vehicle speed is not generated. The sound control device 130 controls the frequency modulator 31 to realize the frequency calculated in process P132. The frequency map is not limited to the example shown in FIG. 5. The frequency map may be created so that the frequency calculated in the map for low gear is higher than the frequency calculated in the map for high gear when compared at the same vehicle speed. For example, as in the example of the sound pressure map shown in FIG. 3, when the vehicle speed exceeds a threshold speed, the increase rate of the frequency with respect to the increase in the vehicle speed may be reduced, or the frequency may be maintained at a constant value regardless of the increase in the vehicle speed.

[0033] The fact that the frequency of the simulated engine sound increases as the gear ratio increases and decreases as the gear ratio decreases is similar to the change in engine sound that occurs with a shift operation in a conventional manual transmission engine vehicle. Therefore, by changing the frequency of the simulated engine sound in response to the driver's gear shift operation using frequency control according to the above modified example, it is possible to meet the expectations of drivers, particularly drivers who are accustomed to conventional manual transmission engine vehicles.

[0034] As another modification, the speaker 32 may be provided with both the amplifier 30 and sound control device 120 shown in Fig. 1 and the frequency modulator 31 and sound control device 130 shown in Fig. 5. In other words, both the sound pressure and frequency of the simulated engine sound may be changed in response to the driver's gear shifting operation. Note that an equalizer may be used instead of a frequency modulator as a device for changing the frequency of the simulated engine sound.

[0035] As a modification of the power system, instead of the transfer case 8, a transmission capable of manually switching between three or more shift positions by the driver may be provided. If the transmission can be manually operated by the driver, it may be a manual transmission in which the driver operates the clutch, a semi-automatic transmission in which a machine operates the clutch instead of the driver, a dual clutch transmission, or a continuously variable transmission. As a modification of the power system, instead of the electric motor 6, a power source other than the electric motor 6 that is quieter than an internal combustion engine, such as a hybrid system (including a plug-in hybrid system), may be provided.

[0036] 2. Second embodiment 2-1. Vehicle control system configuration Fig. 6 is a diagram showing a schematic configuration of a vehicle 200 according to the second embodiment. Among the components of the vehicle 200 shown in Fig. 6, those having the same functions as those of the vehicle 100 according to the first embodiment are given the same reference numerals. Since the configuration of the power system of the vehicle 200 is the same as that of the vehicle 100 according to the first embodiment, the description thereof will be omitted, and the configuration of the control system of the vehicle 200 will be described.

[0037] The vehicle 200 further includes a pseudo shifter 50 in the configuration of the vehicle 100 according to the first embodiment. The pseudo shifter 50 is a dummy different from an actual shifter. The pseudo shifter 50 has a structure similar to a shifter included in a conventional manual transmission engine vehicle. For example, the pseudo shifter 50 may have a structure similar to a shift lever provided on a console, or a structure similar to a shift paddle attached to a steering wheel. Here, the pseudo shifter 50 has a structure similar to a shift lever, and can be moved between shift positions along an H-shaped gate. Since the vehicle 200 does not have an actual transmission, the shift positions of the pseudo shifter 50 are virtual shift positions. In the example shown in FIG. 6, first, second, third, and fourth speeds are provided as virtual shift positions. In a conventional manual transmission engine vehicle, first speed is the shift position with the largest gear ratio, and the gear ratios decrease in the order of second, third, and fourth speeds.

[0038] The vehicle 200 is equipped with a shift position sensor 46. The shift position sensor 46 is provided in the pseudo shifter 50, and outputs a signal indicating a virtual shift position selected by the pseudo shifter 50. The vehicle 200 also has a vehicle speed sensor 40, an accelerator position sensor 42, and a gear position sensor 44. In addition to these sensors, the vehicle 200 is also equipped with many other sensors.

[0039] The vehicle 200 includes a control device 201. Sensors and devices to be controlled mounted on the vehicle 200 are connected to the control device 201 via an in-vehicle network. Like the control device 101 according to the first embodiment, the control device 201 is typically an electronic control unit and includes an interface, a memory, and a processor (not shown). The control device 201 includes a motor control device 210 and a sound control device 220. In detail, the processor functions as at least the motor control device 210 and the sound control device 220 by executing a program stored in the memory by the processor. The processor functioning as the motor control device 210 and the processor functioning as the sound control device 220 may be separate processors or may be the same processor.

[0040] The control target of the motor control device 210 is the inverter 4. A virtual shift position of the pseudo shifter 50 obtained from a signal of the shift position sensor 46 is input to the motor control device 210. The motor control device 210 executes process P211 based on the virtual shift position. In process P211, a virtual gear ratio of the vehicle 200 is determined using a manual transmission engine vehicle model described later. The virtual gear ratio is a gear ratio of the transmission that is virtually realized by torque control of the electric motor 6 using the manual transmission engine vehicle model.

[0041] The gear stage of the transfer case 8 obtained from the signal of the gear stage sensor 44 is input to the motor control device 210. The motor control device 210 executes process P212 based on the gear stage of the transfer case 8 and the virtual gear ratio determined in process P211. In process P212, an overall gear ratio from the electric motor 6 to the transfer case 8 is calculated. The overall gear ratio is a gear ratio obtained by multiplying the gear ratio of the transfer case 8 determined by the gear stage by the virtual gear ratio.

[0042] The motor control device 210 further receives as input the vehicle speed obtained from a signal from the vehicle speed sensor 40 and the accelerator opening obtained from a signal from the accelerator position sensor 42. The motor control device 210 executes process P213 based on the vehicle speed, the accelerator opening, and the overall gear ratio calculated in process P212. In process P213, the torque to be generated in the electric motor 6 is calculated using a manual transmission engine vehicle model. The motor control device 210 inputs the vehicle speed, the accelerator opening, and the overall gear ratio to the manual transmission engine vehicle model, and controls the inverter 4 so that the electric motor 6 generates the torque obtained by the manual transmission engine vehicle model.

[0043] Here, the manual transmission engine vehicle model used by the motor control device 210 will be described with reference to Fig. 7. As shown in Fig. 7, the manual transmission engine vehicle model MOD01 is composed of a transmission model MOD11 and an engine model MOD12. The engine virtually realized by the manual transmission engine vehicle model MOD01 is called a virtual engine, and the transmission virtually realized is called a virtual transmission. The virtual transmission is modeled in the transmission model MOD11. The virtual engine is modeled in the engine model MOD12.

[0044] The transmission model MOD11 calculates a virtual gear ratio. The virtual gear ratio is a gear ratio in the virtual transmission that is determined by the virtual shift position. The virtual gear ratio is set for each virtual shift position. The maximum virtual gear ratio is set for first gear, and the virtual gear ratios are smaller in the order of second gear, third gear, and fourth gear. The transmission model MOD11 calculates a virtual transmission torque using the virtual gear ratio and a virtual engine torque, which will be described later. The virtual transmission torque is a virtual torque output from the virtual transmission. The motor control device 210 controls the inverter 4 so that the output torque of the electric motor 6 is changed according to the virtual transmission torque. The virtual transmission torque changes discontinuously according to the switching of the virtual gear ratio. This discontinuous change in the virtual transmission torque generates a torque shock in the vehicle 200, and the vehicle is made to look like it has a stepped transmission.

[0045] The engine model MOD12 calculates a virtual engine speed and a virtual engine torque. The virtual engine speed is calculated from the vehicle speed and the overall gear ratio. The virtual engine torque is calculated from the virtual engine speed and the accelerator opening. In the engine model MOD12, the relationship between the virtual engine speed and the virtual engine torque is specified for each accelerator opening. The torque characteristics of the engine model MOD12 can be set to characteristics assuming a gasoline engine or to characteristics assuming a diesel engine. In addition, it can be set to characteristics assuming a naturally aspirated engine or to characteristics assuming a supercharged engine.

[0046] Returning to FIG. 6, the configuration of the control system of the vehicle 200 will be further described.

[0047] The object of control of the sound control device 220 is the amplifier 30. The sound control device 220 changes the sound pressure of the simulated engine sound generated from the speaker 32 by controlling the amplifier 30. The sound control device 220, together with the speaker 32 and the amplifier 30, constitutes a sound generator.

[0048] The gear stage of the transfer case 8 obtained from the signal of the gear stage sensor 44 is input to the sound control device 220. The sound control device 220 executes process P221 based on the gear stage. In process P221, a sound pressure map to be used for controlling the amplifier 30 is selected. The sound pressure maps include a low gear map that is selected when the gear stage is L4, and a high gear map that is selected when the gear stage is H4 and when the gear stage is H2. The sound control device 220 selects a sound pressure map according to the current gear stage of the transfer case 8.

[0049] The sound control device 220 further receives as inputs the virtual shift position of the pseudo shifter 50 obtained from the signal of the shift position sensor 46, the vehicle speed obtained from the signal of the vehicle speed sensor 40, and the accelerator opening obtained from the signal of the accelerator position sensor 42. Using the sound pressure map selected in process P221, the sound control device 220 executes process P222 based on the virtual shift position, vehicle speed, and accelerator opening. In process P222, a sound pressure according to the virtual shift position, vehicle speed, and accelerator opening is calculated using the sound pressure map. The sound control device 220 controls the amplifier 30 to realize the sound pressure calculated in process P222.

[0050] FIG. 8 is a diagram showing an example of a sound pressure map according to the second embodiment. In the sound pressure map M02, sound pressure data is set for a vehicle speed so that the sound pressure increases as the vehicle speed increases. Also, sound pressure data is set for a virtual shift position so that the sound pressure increases as the virtual gear ratio increases. The difference between the low-speed gear map M21 and the high-speed gear map M22 is the magnitude of sound pressure for the same vehicle speed. When compared at the same vehicle speed and the same virtual shift position, both maps M21 and M22 are created so that the low-speed gear map M21 has a higher sound pressure and the high-speed gear map M22 has a lower sound pressure. In process P222, the sound pressure is calculated from the vehicle speed using the sound pressure map selected in process P221 from the low-speed gear map M21 and the high-speed gear map M22.

[0051] 2-2. Sound pressure control 9 is a diagram showing the flow of sound pressure control executed by the control device 201 in the vehicle 200. First, in step S201, the gear position of the transfer case 8 is identified. If the gear position is L4, the flow proceeds to step S202, where a map for a low gear is selected. If the gear position is H4 or H2, the flow proceeds to step S203, where a map for a high gear is selected. In step S204, sound pressure data corresponding to the virtual shift position and the vehicle speed is acquired from the sound pressure map selected in step S202 or step S203. Then, in step S205, a simulated engine sound is generated from the speaker 32 in accordance with the sound pressure data acquired in step S204.

[0052] For example, when the gear position of the transfer case 8 is in L4, if the virtual shift position is changed from, for example, 4th gear to 3rd gear by operating the pseudo shifter 50, the sound pressure is increased according to the low gear map M21. When the gear position of the transfer case 8 is in H4, if the virtual shift position is changed from, for example, 4th gear to 3rd gear by operating the pseudo shifter 50, the sound pressure is increased according to the high gear map M22. However, if the vehicle speed is the same, the sound pressure when the virtual shift position is changed to 3rd gear is greater when the gear position of the transfer case 8 is in L4 than when it is in H4. The fact that the sound pressure of the simulated engine sound increases as the overall gear ratio increases is similar to the change in engine sound accompanying shifting operations that occurs in a manually-shifted engine vehicle equipped with a conventional transmission (main transmission) and transfer case (auxiliary transmission). Therefore, by changing the sound pressure of the simulated engine sound in response to the driver's gear shifting operation through the above-mentioned sound pressure control, it is possible to meet the expectations of drivers, particularly drivers who are accustomed to conventional manual gear shift engine vehicles.

[0053] 2-3.Modifications The modified example of the first embodiment shown in FIG. 5 can also be applied to this embodiment. That is, in FIG. 6, the amplifier 30 may be replaced with a frequency modulator, and the sound control device 220 may be replaced with a control device for the frequency modulator. The frequency modulator may be an equalizer. And the sound pressure map may be replaced with a frequency map. In the frequency map, frequency data is set with respect to the vehicle speed so that the higher the vehicle speed, the higher the frequency. Also, frequency data is set with respect to the virtual shift position so that the higher the virtual gear ratio, the higher the frequency. The frequency map includes a map for low speed gears and a map for high speed gears. In the modified example of this embodiment, the difference between the map for low speed gears and the map for high speed gears is the height of the frequency for the same vehicle speed. When compared at the same vehicle speed and the same virtual shift position, both maps are created so that the frequency of the map for low speed gears is higher and the frequency of the map for high speed gears is lower.

[0054] As another modified example, the sound pressure of the simulated engine sound may be changed in response to the driver's gear shifting operation as in the second embodiment, while at the same time, the frequency of the simulated engine sound may be changed in response to the driver's gear shifting operation as in the modified example above.

[0055] 3. Third embodiment 3-1. Vehicle control system configuration Fig. 10 is a diagram showing a schematic configuration of a vehicle 300 according to the second embodiment. Among the components of the vehicle 300 shown in Fig. 10, those having the same functions as the vehicle 100 according to the first embodiment or the vehicle 200 according to the second embodiment are given the same reference numerals. The configuration of the power system of the vehicle 300 is the same as that of the vehicle 100 according to the first embodiment, so a description thereof will be omitted, and the configuration of the control system of the vehicle 300 will be described.

[0056] The vehicle 300 further includes a pseudo clutch pedal 60 in the configuration of the vehicle 200 according to the second embodiment. The pseudo clutch pedal 60 is a dummy that is different from an actual clutch pedal. The pseudo clutch pedal 60 has a structure similar to a clutch pedal that is included in a conventional manual transmission engine vehicle. For example, the pseudo clutch pedal 60 includes a reaction force mechanism that generates a reaction force against the driver's depression. The position when no depression force is applied is the start end position of the pseudo clutch pedal 60, and the position when the pseudo clutch pedal is depressed to the deepest is the end position of the pseudo clutch pedal 60. The driver can operate the pseudo clutch pedal 60 from the start end position to the end position against the reaction force from the reaction force mechanism.

[0057] Although the pseudo clutch pedal 60 is a pedal-type operating device operated by foot, a lever-type operating device or a dial-type operating device operated by hand may also be provided as the pseudo clutch operating device. The pseudo clutch operating device can be operated by the driver against a reaction force from a start position to an end position, and various structures can be adopted as long as the driver can experience the operation feeling of a clutch pedal equipped in a conventional manual transmission engine vehicle with a foot or hand.

[0058] Vehicle 200 is equipped with a clutch position sensor 48. Clutch position sensor 48 is provided on pseudo clutch pedal 60, and outputs a signal indicating the amount of depression of pseudo clutch pedal 60. Since vehicle 200 is not equipped with an actual clutch, the operation amount of pseudo clutch pedal 60, i.e., the clutch opening degree, is a virtual clutch opening degree. Vehicle 300 is also equipped with a vehicle speed sensor 40, an accelerator position sensor 42, a gear stage sensor 44, and a shift position sensor 46. In addition to these sensors, vehicle 300 is also equipped with many other sensors.

[0059] The vehicle 300 includes a control device 301. Sensors and devices to be controlled mounted on the vehicle 300 are connected to the control device 301 via an in-vehicle network. Like the control device 101 according to the first embodiment and the control device 201 according to the second embodiment, the control device 301 is typically an electronic control unit and includes an interface, a memory, and a processor (not shown). The control device 301 includes a motor control device 310 and a sound control device 320. In detail, the processor functions as at least the motor control device 310 and the sound control device 320 by executing a program stored in the memory by the processor. The processor functioning as the motor control device 310 and the processor functioning as the sound control device 320 may be separate processors or may be the same processor.

[0060] The control target of the motor control device 310 is the inverter 4. The motor control device 310 receives the virtual shift position of the pseudo shifter 50 obtained from the signal of the shift position sensor 46 and the gear stage of the transfer case 8 obtained from the signal of the gear stage sensor 44. The motor control device 310 executes process P311 based on the virtual shift position. In process P311, a virtual gear ratio of the vehicle 300 is determined using a manual transmission engine vehicle model described later. Next, the motor control device 310 executes process P312 based on the gear stage of the transfer case 8 and the virtual gear ratio determined in process P211. In process P312, the overall gear ratio is calculated by multiplying the gear ratio of the transfer case 8 determined by the gear stage by the virtual gear ratio.

[0061] In addition, a virtual clutch opening of the pseudo clutch pedal 60 obtained from a signal of the clutch position sensor 48 is input to the motor control device 310. The motor control device 210 executes process P313 based on the virtual clutch opening. In process P313, a virtual clutch torque capacity is calculated using a manual transmission engine vehicle model.

[0062] The motor control device 310 further receives as input the vehicle speed obtained from the signal of the vehicle speed sensor 40 and the accelerator opening obtained from the signal of the accelerator position sensor 42. The motor control device 310 executes process P314 based on the vehicle speed, the accelerator opening, the overall gear ratio calculated in process P312, and the virtual clutch torque capacity calculated in process P313. In process P314, the torque to be generated in the electric motor 6 is calculated from the vehicle speed, the accelerator opening, the overall gear ratio, and the virtual clutch torque capacity using a manual transmission engine vehicle model. The motor control device 210 controls the inverter 4 so that the electric motor 6 generates the torque obtained from the manual transmission engine vehicle model.

[0063] Here, the manual transmission engine vehicle model used by the motor control device 310 will be described with reference to Fig. 11. As shown in Fig. 11, the manual transmission engine vehicle model MOD02 is composed of a transmission model MOD11, an engine model MOD12, and a clutch model MOD13. A clutch virtually realized by the manual transmission engine vehicle model MOD02 is called a virtual clutch. A virtual clutch is modeled in the clutch model MOD13. The contents of the transmission model MOD11 and the engine model MOD12 are the same as those of the manual transmission engine vehicle model MOD01 according to the second embodiment.

[0064] The clutch model MOD13 calculates a torque transmission gain. The torque transmission gain is a gain for calculating the degree of torque transmission of the virtual clutch according to the virtual clutch opening. The virtual clutch opening is 0% at the start position of the pseudo clutch pedal 60 and 100% at the end position of the pseudo clutch pedal 60. In the clutch model MOD13, a torque transmission gain is given for the virtual clutch opening. The torque transmission gain is converted into a clutch torque capacity of the virtual clutch, i.e., a virtual clutch torque capacity. Then, based on a comparison between the virtual clutch torque capacity and the virtual engine torque calculated by the engine model MOD12, a virtual clutch torque input from the virtual clutch to the virtual transmission is calculated. In this embodiment, the transmission model MOD11 calculates the virtual clutch torque by using the virtual gear ratio and the virtual clutch torque.

[0065] Returning to FIG. 10, the configuration of the control system of the vehicle 300 will be further described.

[0066] The object of control of the sound control device 320 is the amplifier 30. The sound control device 320 changes the sound pressure of the simulated engine sound generated from the speaker 32 by controlling the amplifier 30. The sound control device 320, together with the speaker 32 and the amplifier 30, constitutes a sound generator.

[0067] The sound control device 320 receives as input the vehicle speed obtained from the signal of the vehicle speed sensor 40 and the accelerator opening degree obtained from the signal of the accelerator position sensor 42. Furthermore, the sound control device 320 receives as input the overall gear ratio calculated in process P312 and the virtual clutch torque capacity calculated in process P313 from the motor control device 310. The sound control device 220 executes process P321 based on the input information. In process P321, an operating point of the virtual engine represented by the virtual engine speed and the virtual engine torque is calculated. A manual transmission engine vehicle model MOD02 is used to calculate the operating point of the virtual engine.

[0068] The sound control device 320 executes a process P322 based on the operating point of the virtual engine calculated in the process P321. In the process P322, a sound pressure corresponding to the operating point of the virtual engine is calculated using a sound pressure map. The sound control device 320 controls the amplifier 30 so as to realize the sound pressure calculated in the process P322.

[0069] 12 is a diagram showing an example of a sound pressure map according to the third embodiment. In the sound pressure map M03, sound pressure data is set with respect to the virtual engine speed so that the sound pressure increases as the virtual engine speed increases. Also, sound pressure data is set with respect to the virtual engine torque so that the sound pressure increases as the virtual engine torque increases. In the first and second embodiments, a map for a high speed gear and a map for a low speed gear are prepared, but in this embodiment, a common sound pressure map M03 is used regardless of the gear stage of the transfer case 8.

[0070] 3-2. Sound pressure control 13 is a diagram showing the flow of sound pressure control executed by the control device 301 in the vehicle 300. First, in step S301, an overall gear ratio is calculated based on the gear position of the transfer case 8 and the virtual shift position of the pseudo shifter 50. Next, in step S302, an operating point of the virtual engine is calculated using the overall gear ratio calculated in step S301, the vehicle speed, the accelerator opening, and the like. In step S303, sound pressure data corresponding to the operating point of the virtual engine calculated in step S302 is acquired from a sound pressure map. Then, in step S304, a simulated engine sound is generated from the speaker 32 in accordance with the sound pressure data acquired in step S303.

[0071] Fig. 14 is a diagram showing an example of the change in sound pressure due to the above sound pressure control. In the initial state, the vehicle 300 is stopped, the virtual shift position of the pseudo shifter 50 is in first gear, and the gear position of the transfer case 8 is in H4. At time A, the accelerator pedal is depressed and the accelerator opening is opened to 20%. At the same time, from time A, the virtual clutch opening of the pseudo clutch pedal 60 is gradually returned from 100% to 0%. At this time, the sound pressure of the simulated engine sound increases to simulate the engine revving up with the clutch released.

[0072] When the pseudo clutch pedal 60 is released further, a clutch torque capacity of the virtual clutch is generated. With the generation of the clutch torque capacity, torque is generated from the electric motor 6 and the vehicle 300 starts to move forward, and at the same time, the virtual engine speed decreases and the sound pressure of the simulated engine sound is lowered. When the pseudo clutch pedal 60 is released further, the clutch torque capacity increases further and the virtual clutch is fully engaged at time B. After the virtual clutch is fully engaged, the sound pressure of the simulated engine sound increases as the vehicle speed increases. The vehicle 300 continues to coast even after the accelerator opening is returned to 0%. During this time, the simulated engine sound is generated at a volume corresponding to the vehicle speed. Then, at time C, the brake pedal is depressed and the vehicle 300 stops.

[0073] While vehicle 300 is stopped, pseudo clutch pedal 60 is depressed, and the simulated engine state becomes an idle state. While vehicle 300 is stopped, the gear stage of transfer case 8 is switched from H4 to L4. Then, at time D, the accelerator pedal is depressed and the accelerator opening is opened to 20%. At the same time, from time D, the virtual clutch opening of pseudo clutch pedal 60 is gradually returned from 100% to 0%. At this time, the sound pressure of the simulated engine sound is increased to simulate the engine revving up with the clutch released.

[0074] When the simulated clutch pedal 60 is released again, torque is generated from the electric motor 6, and the vehicle 300 starts to move forward, and at the same time the sound pressure of the simulated engine sound is reduced. When the simulated clutch pedal 60 is released again, the virtual clutch is fully engaged at time E. After the virtual clutch is fully engaged, the sound pressure of the simulated engine sound increases as the vehicle speed increases. The vehicle 300 continues to coast even after the accelerator opening is returned to 0%. During this time, the simulated engine sound is generated at a volume that corresponds to the vehicle speed. Then, at time F, the brake pedal is depressed, and the vehicle 300 stops.

[0075] As shown in FIG. 14, when the gear position of the transfer case 8 is in L4, the sound pressure of the simulated engine sound increases more as the vehicle speed increases than when the gear position is in H4. This is because the overall gear ratio increases when the gear position of the transfer case 8 is switched from H4 to L4. When the overall gear ratio increases, the virtual engine speed at the same vehicle speed increases, so the sound pressure of the simulated engine sound is increased according to the sound pressure map M03. By increasing the sound pressure of the simulated engine sound in response to the switching of the gear position of the transfer case 8 from H4 to L4, it is possible to meet the expectations of the driver, especially the driver who is accustomed to conventional manual transmission engine vehicles. In addition, the operation of the pseudo clutch pedal 60 is reflected in the sound pressure calculation of the simulated engine sound, so that the change in sound that the driver expects due to the clutch operation and the change in the simulated engine sound can be made to correspond to each other without any sense of incongruity for the driver.

[0076] 3-3.Modifications The modified example of the first embodiment shown in Fig. 5 can also be applied to this embodiment. That is, in Fig. 10, the amplifier 30 may be replaced with a frequency modulator, and the sound control device 320 may be replaced with a control device for the frequency modulator. The frequency modulator may be an equalizer. And the sound pressure map may be replaced with a frequency map. In the frequency map, frequency data is set with respect to the virtual engine speed so that the frequency increases as the virtual engine speed increases. Also, frequency data is set with respect to the virtual engine torque so that the frequency increases as the virtual engine torque increases.

[0077] As another modified example, while changing the sound pressure of the simulated engine sound in accordance with the operating point of the virtual engine as in the third embodiment, the frequency of the simulated engine sound may be changed in accordance with the operating point of the virtual engine as in the above modified example. [Explanation of symbols]

[0078] 2 battery, 4 inverter, 6 electric motor, 8 transfer case, 10 shift device, 30 amplifier, 31 frequency modulator, 32 speaker, 40 vehicle speed sensor, 42 accelerator position sensor, 44 gear stage sensor, 46 shift position sensor, 48 clutch position sensor, 50 pseudo shifter, 60 pseudo clutch pedal, 101 control device, 110 motor control device, 120 sound control device, 130 sound control device, 201 control device, 210 motor control device, 220 sound control device, 301 control device, 310 motor control device, 320 sound control device

Claims

1. a transmission that is provided between the power source and the drive wheels and that can manually change a gear ratio by a user; A sound generator that artificially generates a sound when the vehicle is running, The sound generator is configured to at least one of increase the frequency of the sound as the speed ratio increases and increase the sound pressure of the sound as the speed ratio increases. A vehicle characterized by:

2. 2. The vehicle according to claim 1, The sound generator is configured to at least one of increase the frequency of the sound as the vehicle speed increases and increase the sound pressure of the sound as the vehicle speed increases. A vehicle characterized by:

3. 2. The vehicle according to claim 1, The sound generator is configured to at least one of increase the frequency of the sound as the accelerator opening degree increases and increase the sound pressure of the sound as the accelerator opening degree increases. A vehicle characterized by:

4. A vehicle according to any one of claims 1 to 3, The power source is an electric motor. A vehicle characterized by:

5. 5. The vehicle according to claim 4, It also has a pseudo shifter that allows you to select multiple virtual shift positions. The sound generator is configured to perform at least one of the following: increasing the frequency of the sound as the virtual shift position selected by the pseudo shifter becomes lower; and increasing the sound pressure of the sound as the virtual shift position selected by the pseudo shifter becomes lower. A vehicle characterized by:

6. 6. The vehicle according to claim 5, The vehicle further includes a motor control device that changes the torque of the electric motor in response to a virtual shift position selected by the pseudo shifter, a vehicle speed, and an accelerator opening degree. The motor control device is configured to increase the torque at the same vehicle speed and the same accelerator opening as the selected virtual shift position is lower, and to limit a vehicle speed range in which the virtual shift position can be selected to a lower speed side. A vehicle characterized by:

7. 5. The vehicle according to claim 4, Further, a pseudo clutch operation device operable against a reaction force from a start position to a terminal position is provided, The sound generator is configured to perform at least one of temporarily lowering the frequency of the sound and temporarily reducing the sound pressure of the sound while the pseudo-clutch operating tool is returned from the end position to the start position. A vehicle characterized by:

8. 8. The vehicle according to claim 7, The vehicle further includes a motor control device that changes the torque of the electric motor in response to an operation amount of the pseudo clutch operation tool, a vehicle speed, and an accelerator opening degree. The motor control device is configured to reduce the torque when the pseudo-clutch operating tool is at the end position, and to generate the torque during the period in which the pseudo-clutch operating tool is returned from the end position to the start position. A vehicle characterized by:

Images