Electric automobile

Abstract

The invention provides an electric vehicle capable of visually notifying a driver of timing of a shift operation in an electric vehicle capable of reproducing the behavior of a transmission vehicle. The present disclosure provides an electric vehicle having an electric motor as a driving source. An electric vehicle is provided with: an accelerator pedal; a simulated shift operation member obtained by simulating an operation member for a shift operation of the transmission vehicle; a display device that performs display facing a driver; a vehicle speed sensor; and a control device that controls the torque of the electric motor in accordance with the operation of the accelerator pedal. The control device performs: switching the relationship between the torque of the electric motor with respect to the accelerator opening degree and the vehicle speed in accordance with the operation of the analog shift operation member; displaying, on a display device, an indicator that continuously changes in conjunction with a drive wheel torque and a vehicle speed; and notifying the driver of the timing for recommending the operation of the simulated shift operation member through the indicator.

Description

Technical Field

[0001] The present disclosure relates to an electric vehicle having an electric motor as a driving source. Background Art

[0002] Patent Document 1 discloses a hybrid vehicle including an instrument display device capable of switching from a power meter display to a tachometer display by operation of a switch.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6947051 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] Electric vehicles are known that can simulate the behavior of a vehicle equipped with a manual transmission (a transmission vehicle) powered by an engine by controlling an electric motor. These electric vehicles also replicate the gear shifting of a transmission vehicle, allowing the driver to manually perform simulated shifting operations. In such vehicles, it is considered possible to easily inform the driver of the timing of the shifting operation.

[0008] One object of the present disclosure is to provide a technology capable of visually notifying a driver of the timing of switching of a virtually reproduced gear stage in an electric vehicle capable of reproducing the behavior of a transmission vehicle.

[0009] Means for solving problems

[0010] The present disclosure provides an electric vehicle having an electric motor as a drive source. The electric vehicle includes: an accelerator pedal for driving; a simulated speed change operating member that simulates the speed change operation of a transmission vehicle; a display device for providing a display to the driver; a vehicle speed sensor that measures the speed of the electric vehicle; and a control device that controls the torque of the electric motor in accordance with the operation of the accelerator pedal. The control device is configured to: switch the relationship between the torque of the electric motor and the accelerator opening and the vehicle speed in accordance with the operation of the simulated speed change operating member; display an indicator on the display device that continuously changes in conjunction with the drive wheel torque and the vehicle speed; and notify the driver of the timing of the recommended operation of the simulated speed change operating member through the above-mentioned indicator.

[0011] Effects of the Invention

[0012] According to the electric vehicle disclosed herein, the timing of a recommended speed shift operation, simulated by a simulated speed shift operating member, is notified by an indicator displayed on a display device. Furthermore, the display of the indicator changes continuously according to the vehicle's state. By notifying the recommended speed shift operation timing in a single burst, but rather through a display that continuously changes in accordance with the vehicle's state, the driver can visually and easily grasp the timing of the speed shift operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a diagram showing the structure of an electric vehicle according to an embodiment of the present disclosure.

[0014] Figure 2 This is a diagram showing the configuration of a control device related to driving control of an electric vehicle.

[0015] Figure 3 This is a graph showing the relationship between the virtual engine speed and the virtual engine torque.

[0016] Figure 4 It is a diagram for explaining indicators displayed on the electric vehicle according to the embodiment of the present disclosure.

[0017] Figure 5 : is a diagram showing an example of a map for determining the length of a bar.

[0018] Figure 6 This is a diagram for explaining changes in mapping based on a schema.

[0019] Figure 7 It is a diagram showing an example of a display on an indicator.

[0020] Figure 8 This is a diagram showing another example of the display on the indicator.

[0021] Figure 9 It is a diagram showing an example of changes in the display of the indicator. DETAILED DESCRIPTION

[0022] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0023] 1. The structure of the electric vehicle power system

[0024] Figure 1 Schematically shows the structure of the electric vehicle 100 according to the embodiment of the present disclosure. Figure 1 The configuration of the power system of the electric vehicle 100 will be described.

[0025] Electric vehicle 100 is equipped with two electric motors (M) 4F and 4R at the front and rear as propulsion sources. Electric motors 4F and 4R are, for example, three-phase AC motors. Front electric motor 4F is connected to front drive shaft 5F, which drives front wheels 6F. Rear electric motor 4R is connected to rear drive shaft 5R, which drives rear wheels 6R. Front wheels 6F are suspended on left and right independent electronically controlled front suspension 7F. Rear wheels 6R are suspended on left and right independent electronically controlled rear suspension 7R.

[0026] Inverters (INV) 3F and 3R are mounted on the front electric motor 4F and the rear electric motor 4R, respectively. The front inverter 3F and the rear inverter 3R are each connected to a battery (BATT) 2. Battery 2 stores electrical energy for driving electric motors 4F and 4R. In other words, electric vehicle 100 is a battery electric vehicle (BEV) that uses the electrical energy stored in battery 2 to travel. Inverters 3F and 3R are, for example, voltage-type inverters, and control the torque of electric motors 4F and 4R through PWM control.

[0027] 2. The structure of the electric vehicle control system

[0028] Next, refer to Figure 1 The configuration of the control system of the electric vehicle 100 will be described.

[0029] The electric vehicle 100 includes a battery management system (BMS) 10 . The BMS 10 is a device that monitors the cell voltage, current, temperature, etc. of the battery 2 . The BMS 10 has a function of estimating the state of charge (SOC) of the battery 2 .

[0030] The electric vehicle 100 includes a vehicle speed sensor 11. At least one of the wheel speed sensors (not shown) provided on each of the left and right front wheels 6F and the left and right rear wheels 6R serves as the vehicle speed sensor 11. Furthermore, the electric vehicle 100 includes an accelerator pedal stroke sensor 12. The accelerator pedal stroke sensor 12 is provided on the accelerator pedal 22 and outputs a signal indicating the amount of depression on the accelerator pedal 22, i.e., the accelerator opening. Furthermore, the electric vehicle 100 includes a brake pedal stroke sensor 13. The brake pedal stroke sensor 13 is provided on the brake pedal 23 and outputs a signal indicating the amount of depression on the brake pedal 23, i.e., the brake opening.

[0031] The accelerator pedal 22 and the brake pedal 23 are operating components used to operate the electric vehicle 100. Unlike these operating components, the electric vehicle 100 includes simulated shifting components that simulate the shifting operations used in transmission vehicles. These simulated shifting components include a simulated H-type shifter 24, a simulated lever shifter 25, and a simulated clutch pedal 26.

[0032] The simulated H-shaped shifter 24 is a virtual shifter, different from a typical H-shaped shifter. It has a structure similar to a shift lever mounted on a console and can move along an H-shaped gate between gear positions. However, since the electric vehicle 100 does not have a physical transmission, the gear positions of the simulated H-shaped shifter 24 are imaginary. The simulated H-shaped shifter 24 is equipped with a gear position sensor 14. The gear position sensor 14 outputs a signal indicating the gear position selected by the simulated H-shaped shifter 24.

[0033] The simulated lever shifter 25 is a virtual shifter, different from a conventional lever shifter, which is a type of sequential shifter. It has a structure similar to paddle shifters mounted on a steering wheel, enabling independent movement of the left and right paddles. The simulated lever shifter 25 is equipped with a paddle shift switch 15. The paddle shift switch 15 outputs an upshift signal when the right paddle is pulled, and a downshift signal when the left paddle is pulled.

[0034] The simulated clutch pedal 26 is a virtual clutch pedal that is different from the original clutch pedal. The simulated clutch pedal 26 has a structure similar to the clutch pedal of an existing transmission vehicle. For example, the simulated clutch pedal 26 has a reaction force mechanism that generates a reaction force relative to the driver's stepping. The position when no pedal force is applied is the starting position of the simulated clutch pedal 26, and the position when it is stepped on to the innermost side is the terminal position of the simulated clutch pedal 26. The driver can operate the simulated clutch pedal 26 from the starting position to the terminal position by overcoming the reaction force from the reaction force mechanism. A clutch pedal stroke sensor 16 is provided on the simulated clutch pedal 26. The clutch pedal stroke sensor 16 outputs a signal indicating the amount of stepping on the simulated clutch pedal 26. The electric vehicle 100 does not have a real clutch, so the operation amount of the simulated clutch pedal 26, that is, the clutch opening, is a virtual clutch opening.

[0035] The simulated clutch pedal 26 is a pedal-type operating device operated by foot, but a lever-type operating device or a dial-type operating device operated by hand may also be used as the simulated clutch operating device. The simulated clutch operating device allows the driver to operate from the initial position to the final position against the reaction force, and various structures can be used as long as the driver can feel the same operating feel as the clutch pedal of a conventional transmission vehicle with the foot or hand.

[0036] The electric vehicle 100 also includes a human-machine interface (HMI) 20, which serves as an interface with the driver; a display device 21; and an in-vehicle speaker 27. The HMI 20 includes a touch panel display. The HMI 20 displays information on the touch panel display and accepts input from the driver through touch operations on the touch panel display. The display device 21 is provided, for example, on the instrument panel and can display a reproduction of the transmission vehicle status in the MT mode (described later). The in-vehicle speaker 27 can provide information to the driver via voice and output a simulated engine sound (described later).

[0037] Electric vehicle 100 includes a control device 101. Sensors and controlled devices installed in electric vehicle 100 are connected to control device 101 via an in-vehicle network. In addition to a battery management system 10, a vehicle speed sensor 11, an accelerator pedal travel sensor 12, a brake pedal travel sensor 13, a gear position sensor 14, a paddle shift switch 15, and a clutch pedal travel sensor 16, various other sensors are also installed in electric vehicle 100.

[0038] The control device 101 is typically an electronic control unit (ECU). The control device 101 may also be a combination of multiple ECUs. The control device 101 includes at least a processor 102 and a memory 103. The memory 103 includes a RAM for temporarily recording data and a ROM for storing a program 104 executable by the processor 102 and various data 105 associated with the program. The program 104 is composed of multiple instructions. The processor 102 reads the program 104 and data 105 from the memory 103 and executes them, generating control signals based on signals obtained from various sensors. The control device 101 may include one or more processors 102.

[0039] The control device 101 can control the electric vehicle 100 in various control modes. The driver can select a control mode by touching the touch panel display of the HMI 20. Specifically, each touch operation on the touch panel display of the HMI 20 causes one or more programs 104 associated with each touch operation to be read from the memory 103 and executed by the processor 102. The following describes the control modes of the electric vehicle 100 that the driver can select by operating the HMI 20.

[0040] 3. Electric vehicle control mode

[0041] The control modes of the electric vehicle 100 selectable by the control device 101 include the EV mode and the MT mode. The driver can select the control mode from a selection screen displayed on the touch panel display of the HMI 20.

[0042] When EV mode is selected, the control mode of electric vehicle 100 switches to EV mode. EV mode is a mode in which the electric motor is controlled using normal torque characteristics for driving. In EV mode, the driver can basically drive electric vehicle 100 simply by operating the accelerator pedal 22, brake pedal 23, and a steering wheel (not shown). In EV mode, shifting operations using the simulated H-type shifter 24, shifting operations using the simulated lever shifter 25, and clutch operation using the simulated clutch pedal 26 are disabled.

[0043] When the MT mode is selected, the control mode of the electric vehicle 100 switches to the MT mode. The MT mode is a control mode for operating the electric vehicle 100 like a transmission vehicle. In the MT mode, a virtual gear position (gear stage) is reproduced, and the driver can manually perform simulated gear shifting operations.

[0044] In MT mode, the driver can select a more detailed control mode. For example, the driver is able to select an option regarding the shifting mode of the manual transmission reproduced by the electric vehicle 100. The shifting mode includes a paddle shift mode and a lever shift mode. The paddle shift mode refers to a mode in which the simulated handle shifter 25 is used for the shifting operation. In the paddle shift mode, the shifting operation of the simulated H-type shifter 24 is invalidated. In the paddle shift mode, the action when the gear ratio of the manual transmission is switched is reproduced by the shifting operation of the simulated handle shifter 25. In addition, the clutch operation in the real paddle shift type manual transmission is automatically performed by a robot. Therefore, in the paddle shift mode, the clutch operation of the simulated clutch pedal 26 is not required. In the paddle shift mode, the clutch operation of the simulated clutch pedal 26 is invalidated.

[0045] The lever shift mode is a mode in which the simulated H-type shifter 24 is used for shifting operations. In the lever shift mode, the shifting operation of the simulated lever shifter 25 is invalidated. In the lever shift mode, the action when the gear ratio of the manual transmission is switched is reproduced by the shifting operation of the simulated H-type shifter 24. In the lever shift mode, the driver can also choose between clutch operation or clutchless operation. Among the true H-type shifter type manual transmissions, there are manual transmissions in which the driver himself performs the clutch operation and manual transmissions in which the clutch operation is handed over to a robot. When clutch operation is selected, the lever shift mode switches to a mode that requires clutch operation of the simulated clutch pedal 26. On the other hand, when the clutchless operation lever is selected, the clutch operation of the simulated clutch pedal 26 is invalidated, and the lever shift mode switches to a mode that does not require clutch operation.

[0046] The driver can also select options related to engine characteristics, engine sound, drive mode, suspension characteristics, and the like. By appropriately combining these options, the driver can determine the characteristics of a transmission vehicle that they want the electric vehicle 100 to simulate. In this way, by operating the touch panel display of the HMI 20, the control mode of the electric vehicle 100 can be switched to the driver's preference.

[0047] Such a control mode switched by the driver is related to the travel control of the electric vehicle 100. In the next chapter, the travel control of the electric vehicle 100 by the control device 101 will be described.

[0048] 4. Driving control of electric vehicles

[0049] Figure 2 1 is a diagram showing the structure of a control device 101 related to the driving control of an electric vehicle 100. In detail, Figure 2 The configuration related to torque control in particular in driving control is shown. The processor 102 functions as a driving control device by executing one or more driving control programs 104 stored in the memory 103 .

[0050] A control mode signal is input from HMI 20 to control device 101, which serves as a driving control device. The control mode signal includes information regarding the control mode selected by the driver. Control device 101 executes process P110 based on the control mode signal. In process P110, the control mode is switched based on the control mode signal. Among control mode switches, switching between EV mode and MT mode particularly affects driving control.

[0051] When the control mode is switched to EV mode, control device 101 executes process P120 for calculating torque in EV mode. In process P120, control device 101 obtains vehicle speed from the signal of vehicle speed sensor 11 and accelerator pedal position from the signal of accelerator pedal stroke sensor 12. Control device 101 has a motor torque map that uses accelerator position and vehicle speed as parameters. Control device 101 inputs vehicle speed and accelerator position into the motor torque map and controls inverters 3F and 3R to cause electric motors 4F and 4R to generate torques obtained from the motor torque map.

[0052] When the control mode is switched to MT mode, the control device 101 executes process P130 for calculating torque in MT mode. Process P130 includes process P131 for calculating the torque generated by the drive wheels. Process P130 also includes processes P132 and P133. Process P132 calculates the torque generated by the front electric motor 4F, while process P133 calculates the torque generated by the rear electric motor 4R. Processes P132 and P133 are executed based on the drive wheel torque calculated in process P130 and the torque distribution between the front wheels 6F and the rear wheels 6R.

[0053] The vehicle model MOD01 is used to calculate the drive wheel torque in process P131. The vehicle model MOD01 includes an engine model MOD11, a clutch model MOD12, and a transmission model MOD13. The engine hypothesized by the vehicle model MOD01 is referred to as a virtual engine, the clutch hypothesized as a virtual clutch, and the transmission hypothesized as a virtual transmission. The virtual engine is modeled in the engine model MOD11. The virtual clutch is modeled in the clutch model MOD12. The virtual transmission is modeled in the transmission model MOD13.

[0054] The engine model MOD11 calculates the hypothetical engine speed and hypothetical engine torque. The hypothetical engine speed is calculated based on the vehicle speed, the comprehensive reduction ratio, and the slip ratio of the hypothetical clutch. The hypothetical engine torque is calculated based on the hypothetical engine speed and the accelerator opening. The vehicle speed is obtained from the signal of the vehicle speed sensor 11. The accelerator opening is obtained from the signal of the accelerator pedal stroke sensor 12. The comprehensive reduction ratio is a value obtained by multiplying the speed ratio of the hypothetical transmission by the reduction ratio determined by the mechanical structure from the hypothetical transmission to the drive wheels. In the engine model MOD11, the relationship between the hypothetical engine speed and the hypothetical engine torque is specified for each accelerator opening. Alternatively, the driver can select the engine characteristics of the engine model MOD11 by operating the HMI20.

[0055] The clutch model MOD12 calculates the torque transfer gain. The torque transfer gain is a gain used to calculate the degree of torque transfer of the virtual clutch corresponding to the clutch opening. When the lever shift mode with clutch operation is selected as the shift mode, the clutch opening is obtained from the signal of the clutch pedal stroke sensor 16. The clutch opening is 0% at the starting position of the simulated clutch pedal 26 and 100% at the end position of the simulated clutch pedal 26. In the clutch model MOD12, the torque transfer gain is assigned to the clutch opening. The torque transfer gain is converted into the clutch torque capacity of the virtual clutch, i.e., the virtual clutch torque capacity. Then, based on the comparison of the virtual clutch torque capacity with the virtual engine torque calculated by the engine model MOD11, the virtual clutch torque input from the virtual clutch to the virtual transmission is calculated. In addition, the clutch model MOD12 calculates the slip ratio by subtracting the torque transfer gain from 1. The slip ratio is used to calculate the virtual engine speed in the engine model MOD11.

[0056] When the paddle shift mode is selected, the clutch operation model is used to calculate the clutch opening input to clutch model MOD12. Furthermore, when the clutchless shift mode is selected, the clutch operation model is also used to calculate the clutch opening input to clutch model MOD12. The clutch operation model simulates the driver's clutch operation. When the paddle shift mode is selected, the clutch operation model receives inputs of vehicle speed, virtual engine speed, and a signal from the paddle shift switch 15. When the clutchless shift mode is selected, the clutch operation model receives inputs of vehicle speed, virtual engine speed, and a signal from the gear position sensor 14.

[0057] Signals from the paddle shift switches 15 and the gear position sensor 14 are used to measure clutch operation timing. When the driver's shift operation is detected based on the signals from the paddle shift switches 15 and the gear position sensor 14, the clutch operation model sets the clutch opening to its maximum value, disengaging the virtual clutch. Vehicle speed and virtual engine rpm are used to calculate the clutch opening. To ensure smooth alignment between the virtual transmission input shaft speed calculated based on vehicle speed and the virtual engine rpm, the clutch operation model calculates the clutch opening based on the speed difference between the virtual transmission input shaft speed and the virtual engine rpm.

[0058] The transmission model MOD13 calculates a virtual speed ratio. This virtual speed ratio is determined by the virtual gear position (virtual gear stage) in the virtual transmission. A virtual speed ratio is set for each gear position. The maximum virtual speed ratio is set for first gear, and the virtual speed ratio decreases in order of second, third, fourth, and so on. In the lever shift mode, the gear positions correspond one-to-one to the signals from the gear position sensor 14.

[0059] In paddle shift mode, an upshift signal from the paddle shift switch 15 causes the gear to be upshifted one step, and a downshift signal from the paddle shift switch 15 causes the gear to be downshifted one step. Furthermore, while the number of gears in the simulated H-type shifter 24 is physically determined, the number of gears in the simulated lever shifter 25 is not physically restricted. Therefore, the transmission model MOD13 can be configured differently for lever shift mode and paddle shift mode, with the paddle shift mode providing a greater number of gears than the lever shift mode.

[0060] Transmission model MOD13 calculates a virtual transmission torque using a virtual speed ratio and a virtual clutch torque. The virtual transmission torque is the virtual torque output from the virtual transmission. Control device 101 controls inverters 3F and 3R so that the output torque of electric motors 4F and 4R varies according to the virtual transmission torque. The virtual transmission torque varies discontinuously with the switching of the virtual speed ratio. This discontinuous variation in the virtual transmission torque causes torque shock in electric vehicle 100, suggesting the possibility of a vehicle equipped with a stepped transmission.

[0061] The vehicle model MOD01 calculates the drive wheel torque based on the hypothetical transmission torque and the reduction ratio. The drive wheel torque is the sum of the torques acting on the left and right front wheels 6F and the left and right rear wheels 6R. The torque distribution between the front and rear wheels 6F and 6R can be fixed or actively or passively variable. The torque distribution can also be selected by the driver. When the rear-wheel-only drive mode is selected, the drive wheel torque is the sum of the torques acting on the left and right rear wheels 6R.

[0062] In process P132, the torque of the front electric motor 4F in the MT mode (front motor torque) is calculated by multiplying the drive wheel torque calculated in process P131 by the torque distribution rate to the front wheels 6F and the reduction ratio from the output shaft of the front electric motor 4F to the front wheels 6F. The control device 101 controls the front inverter 3F so that the front electric motor 4F generates the front motor torque calculated in process P132.

[0063] In process P133, the torque of the rear electric motor 4R in the MT mode (rear motor torque) is calculated by multiplying the drive wheel torque calculated in process P131 by the torque distribution rate to the rear wheels 6R and the reduction ratio from the output shaft of the rear electric motor 4R to the rear wheels 6R. The control device 101 controls the rear inverter 3R so that the rear electric motor 4R generates the rear motor torque calculated in process P133.

[0064] In addition, Figure 2 In the illustrated configuration, the battery management system 10 and brake pedal travel sensor 13 are not necessarily required to perform the aforementioned driving control. However, if the control mode switch affects the SOC of battery 2, the signal from the battery management system 10 can be used as information to determine whether the control mode switch is appropriate. Furthermore, if the operating method of electric vehicle 100 significantly changes, such as when switching between EV mode and MT mode, the presence of a depressed brake pedal 23 can be used as a switching condition. In this case, the signal from the brake pedal travel sensor 13 can be used as information to determine whether the brake pedal 23 is depressed.

[0065] 5. Voice control for electric vehicles

[0066] The control device 101 can also perform sound control, controlling the sound emitted by the in-vehicle speaker 27. When the processor 102 executes one or more sound control programs 104 stored in the memory 103, the processor 102 functions as a sound control device. The processor 102 that functions as the torque control device and the processor 102 that functions as the sound control device can be different processors or the same processor.

[0067] The control device 101, as a sound control device, can generate artificial sounds from the in-vehicle speaker 27. One of these artificial sounds is a simulated engine sound similar to the engine sound of a transmission vehicle. When a control mode signal indicating that the MT mode is selected is input from the HMI 20, the control device 101, as the sound control device, generates the simulated engine sound based on the virtual engine torque and virtual engine speed calculated in process P131.

[0068] When the driver can select an engine sound, the engine sound selected by HMI 20 is used as the sound source for the simulated engine sound produced by in-vehicle speaker 27. However, the sound source sound is not used directly. Instead, the sound pressure of the engine sound is calculated so that the sound pressure increases with the assumed engine torque, and the frequency of the engine sound is calculated so that the frequency increases with the assumed engine speed. The simulated engine sound is then reproduced from in-vehicle speaker 27 by, for example, varying the sound pressure of the sound source using an amplifier and varying the frequency of the sound source using a frequency modulator. The simulated engine sound is then reproduced from in-vehicle speaker 27. The assumed engine torque and speed vary according to the driver's accelerator, gearshift, and clutch operation. By varying the sound pressure and frequency of the simulated engine sound in accordance with the driver's operation, the driver can experience a sense of reality, similar to driving a real transmission vehicle.

[0069] 6. Notification of Shift Operation Timing (First Embodiment)

[0070] As described above, the driver of electric vehicle 100 switches the control mode to MT mode by operating HMI 20, allowing the driver to experience the operation of a transmission vehicle in electric vehicle 100. In MT mode, the driver can manually perform simulated gear shifting (shifting) to switch between virtual gears as part of the simulation of the operation of a transmission vehicle.

[0071] In typical transmission vehicles, the timing of the gearshift operation is not explicitly notified. However, the driver can determine the timing of the gearshift based on vehicle speed, engine rpm, and other factors. The concept of timing the gearshift operation in the MT mode of electric vehicle 100 is essentially the same. That is, even without explicit notification, the driver can determine the timing of the gearshift based on vehicle speed, hypothetical engine rpm, and other factors, and select a gear that matches the hypothetical state of the transmission vehicle. However, visual notification of the timing of the gearshift operation would be more convenient for the driver.

[0072] Therefore, the electric vehicle 100 notifies the driver of the timing suitable for the gear shift operation by displaying the information on the display device 21. The notification by the electric vehicle 100 will be described below.

[0073] The timing of the speed change operation can be considered based on the magnitude of the virtual engine speed and the virtual engine torque. Figure 3 This is a graph showing the relationship between the virtual engine speed and the maximum virtual engine torque. The maximum virtual engine torque relative to the virtual engine speed is determined by the vehicle model MOD01, and the shaded area represents a region where the virtual engine torque can be taken.

[0074] Within the shaded area, the ellipse (1) represents an approximate area where downshifting is recommended, the ellipse (2) represents an approximate area when a gear matching the state of the hypothetical transmission vehicle is selected, and the ellipse (3) represents an approximate area where upshifting is recommended. When the hypothetical engine speed and hypothetical engine torque are in the area (1), it is believed that downshifting allows the driver to drive more comfortably with a larger torque. When the hypothetical engine speed and hypothetical engine torque are in the area (2), it is believed that the driver can drive in an area where the torque can be fully utilized. When the hypothetical engine speed and hypothetical engine torque are in the area (3), it is believed that upshifting allows the driver to drive comfortably because the driver has passed through an area where the hypothetical engine torque can be maximized.

[0075] The white arrows within the shaded area represent the changes in virtual engine speed and virtual engine torque when the driver depresses the accelerator pedal 22 in a certain virtual gear position. The lower left side of the arrow represents the range where downshifting is comfortable. As the accelerator pedal 22 is depressed from this position, the virtual engine speed and virtual engine torque gradually increase, shifting into a range where the current gear position is considered appropriate. If the virtual engine speed and virtual engine torque continue to rise with further depression of the accelerator pedal 22, the vehicle enters the range where upshifting is recommended.

[0076] An indicator showing the change in the virtual engine speed and the virtual engine torque by a change in the length of a bar is displayed on the display device 21 , and the recommended gear shift timing is notified by the change in the length of the bar.

[0077] exist Figure 4 The figure shows how the length of the bar changes in accordance with the change of the imaginary engine speed and the imaginary engine torque. The positions of (a) to (d) in the upper coordinate diagram correspond to the displays of (a) to (d) below. Figure 4 As shown, when the hypothetical engine speed and torque are to the lower left of the white arrow, the length of the bar shortens. As the hypothetical engine speed and torque increase, the length of the bar gradually lengthens. Furthermore, the possible end positions of the bar are divided into three zones: a downshift recommendation zone (recommending a downshift), a zone recommending the current gear, and an upshift recommendation zone (recommending an upshift). When the end position enters the upshift recommendation zone, an upshift timing is notified, while when it enters the downshift recommendation zone, a downshift timing is notified.

[0078] In this way, the timing of the recommended shift operation is visually notified to the driver through the change in the length of the bar. In addition, the length of the bar changes continuously according to the state of the virtual transmission vehicle reproduced in MT mode. Therefore, the driver can also know from the display how much margin there is before reaching the recommended downshift or upshift area, thereby easily and intuitively grasping the timing of the shift operation. Figure 4 In the example, states (b) and (c) are both in the appropriate range for the current gear position. However, state (b) has some margin before reaching the recommended upshift range, while state (c) has less margin. This is an effect that cannot be achieved with a device that only notifies the timing of the gear shift operation once.

[0079] It should be noted that the imaginary engine speed and imaginary engine torque do not necessarily follow the Figure 3 and Figure 4 Although the white arrows shown change, even if the positions indicating the virtual engine speed and virtual engine torque are not on the white arrows, the current virtual engine speed and virtual engine torque can be replaced with the length of the bar. Specifically, the current virtual engine speed and virtual engine torque can be used to predict the margin between the time when the accelerator pedal 22 is depressed and the time when an upshift is initiated, or the margin between the time when the accelerator pedal 22 is released and the time when a downshift is initiated. This can be replaced with the length of the bar. Consequently, the length of the bar can be determined based on where the virtual engine speed and virtual engine torque fall within the range, and the recommended shift timing can be communicated using the continuously changing length of the bar.

[0080] use Figure 5 The calculation method of the bar length is described. Figure 5 This is a mapping of the length of the bar corresponding to the hypothetical engine speed and the hypothetical engine torque. The color concentration indicates the length of the bar. The lighter the color, the shorter the bar, and the darker the color, the longer the bar. From the perspective of the same hypothetical engine speed, the greater the hypothetical engine torque, the longer the bar. From the perspective of the same hypothetical engine torque, the greater the hypothetical engine speed, the longer the bar. In addition, Figure 5 In the illustrated map, the values representing the magnitude of the virtual engine speed and virtual engine torque are not limited to the values corresponding to the virtual engine speed and virtual engine torque calculated by vehicle model MOD01. For example, the virtual engine speed and virtual engine torque values may be replaced with scores, or the map may be set based on the scores. The map is prepared in advance and stored in memory 103. The length of the bar is calculated based on the virtual engine speed and virtual engine torque values based on this map.

[0081] 7. Other Implementation Methods

[0082] 7-1. Second embodiment

[0083] The above is a basic embodiment. Various embodiments will be described below as modified examples. In the second embodiment, the map that determines the length of the bar is variable according to the driving mode.

[0084] exist Figure 6: An example of three driving modes and their corresponding mappings is shown in FIG. As driving modes, three modes can be selected: normal mode, economy mode, and sport mode. The upper mapping represents the mapping in normal mode, the lower left mapping represents the mapping in economy mode, and the lower right mapping represents the mapping in sport mode. Normal mode is a mapping corresponding to the timing of general gear shifting. In economy mode, the length of the bar becomes longer from the area where the hypothetical engine torque is low compared to normal mode. That is, a notification is made to recommend an upshift based on relatively low hypothetical engine speed and hypothetical engine torque. By promoting early upshifting in this way, the output of the drive wheel torque can be suppressed, and the consumption of battery 2 can be suppressed. Sport mode is a mode that promotes so-called "traction driving" and can suppress the extension of the bar when the hypothetical engine speed becomes high compared to normal mode. That is, the timing of upshifting is later than that in normal mode.

[0085] In this way, by making the mapping variable in accordance with the driving mode, the timing of the gear shift that matches the driver's preferences and conditions can be notified. In addition, when changing the mapping in accordance with the driving mode, the length of the bar set for the same virtual engine speed and virtual engine torque can be changed, and the calculation method of the score based on the virtual engine speed and virtual engine torque can be changed. In addition, the driver can operate HMI20 to arbitrarily select each driving mode. Alternatively, it can be automatically changed by the control device 101. For example, the control device 101 can also obtain information from the battery management system 10 and automatically set the driving mode to the economic mode when the battery remaining power is low. In addition, the three driving modes mentioned above are an example, and the driving modes and the corresponding mappings can be more or less than three, and the prepared mappings are not limited to. Figure 6 The mapping shown.

[0086] 7-2. Third embodiment

[0087] The third embodiment is a modification of the second embodiment. In the second embodiment, the timing of the notification urging upshifts and downshifts is variable according to the driving mode. In contrast, in the third embodiment, the rate of change of the bar length is variable according to the driving mode.

[0088] For example, maps corresponding to two driving modes, normal mode and strong notification mode, are prepared. The virtual engine speed and virtual engine torque when the end position of the bar enters the downshift recommendation zone or upshift recommendation zone are set to be equal in both maps. In other words, the timing of the notification urging a downshift or upshift is the same in both modes. However, in strong notification mode, the rate of change in the length of the bar near the downshift recommendation zone or upshift recommendation zone increases. The bar length changes dramatically when entering the recommended shift zone, making it easier for the driver to visually perceive that a notification is in progress.

[0089] These two modes can be selected arbitrarily by the driver or automatically set by the control device 101. Furthermore, the third embodiment can also be combined with the second embodiment. Specifically, both the timing of the shift notification and the speed of change in the length of the bar near the recommended upshift region or recommended downshift region can be made variable according to the driving mode.

[0090] 7-3. Fourth Embodiment (Variation of Display Method)

[0091] The indicator displayed on the display device 21 is not limited to an indicator represented by a linear bar. Figure 7 : is a diagram showing an example of a bar display method. The bar may be displayed in a curved line within a circular display area.

[0092] Furthermore, the color of the bar in the indicator can also change as the bar length changes. For example, the color of the bar can change continuously as the bar length changes. Alternatively, the color of the bar can change in stages as the end of the bar enters the downshift recommendation zone or upshift recommendation zone. Alternatively, the bar can flash in conjunction with or in lieu of a color change when the end of the bar enters the downshift recommendation zone or upshift recommendation zone. This color change or flashing makes it easier for the driver to understand that the downshift recommendation zone or upshift recommendation zone has been entered.

[0093] In addition, the display of the indicator may not be based on a bar. Figure 8 In this example, the recommended downshift area, recommended upshift area, and area where appropriate gears can be selected are represented by circular areas. The blackened circular area represents the current state of the hypothetical transmission vehicle, and its size changes continuously as the hypothetical transmission vehicle state changes. Display can also be represented by changing area in this way.

[0094] As such, the indicator can be displayed in any manner as long as it can visually capture the continuous changes corresponding to the state of the hypothetical transmission vehicle. Examples of indicators include numerical values, colors, graphic areas, bar lengths, or combinations thereof that continuously change. In addition, when using a display other than bar length as an indicator, a display may also be used. Figure 5 The parameters to be displayed are calculated by the mapping shown. For example, Figure 5 Such mapping is used to define area and color.

[0095] 7-4. Fifth embodiment (divided areas)

[0096] exist Figure 4In the example, the possible positions of the end of the bar are divided into three zones: a downshift recommended zone, an upshift recommended zone, and a zone where no shifting is required. By simply dividing the shift timing into three zones, it is easier for the driver to clearly grasp the shift timing.

[0097] The size of each of these three areas can also be changed according to the driver's selection. Figure 9 Examples of zone division methods are shown. (e) shows the zone division method for the normal mode. In contrast, (f) shows the zone division method for a mode designed for drivers who actively downshift. In this example, the downshift recommendation zone is wider than in the normal mode, while the upshift recommendation zone is narrower. Thus, the size of each zone can be variable.

[0098] Furthermore, the indicator display shows that the possible end positions of the bar can be further divided into sub-areas. For example, in example (g), the possible end positions of the bar are divided into four areas: a downshift recommended area, a large output margin area, an area where driving in an appropriate gear is possible, and an upshift recommended area. The "large output margin" area indicates that there is margin to the maximum virtual engine torque and that the accelerator pedal 22 is depressed. Within this area, driving can continue in the current virtual gear, or downshifting can be performed to obtain greater acceleration. By displaying this area in addition to the downshift recommended area, it can serve as a reference for drivers who want to actively downshift.

[0099] In this way, by displaying the further subdivided areas of the indicator, the driver can understand the state of the virtual transmission vehicle in more detail. It should be noted that the display of the indicator can be fixed to any of the three areas or a further subdivided display, and can also be switched arbitrarily by the driver or automatically by the control device 101.

[0100] 8. Summary

[0101] As described above, the electric vehicle according to this embodiment notifies the driver of the recommended timing for switching to a hypothetical gear position via a continuously changing display. Since the display continuously changes in accordance with the state of the hypothetical transmission vehicle, the driver can visually and easily grasp the timing of the gear shift operation reproduced in MT mode. This improves drivability. Furthermore, the various embodiments described above can be appropriately combined.

[0102] Description of Reference Numerals

[0103] 2 Battery, 3F Front Inverter, 3R Rear Inverter, 4F Front Electric Motor, 4R Rear Electric Motor, 5F Front Drive Shaft, 5R Rear Drive Shaft, 6F Front Wheel, 6R Rear Wheel, 7F Front Suspension, 7R Rear Suspension, 10 Battery Management System, 11 Vehicle Speed Sensor, 12 Accelerator Pedal Travel Sensor, 13 Brake Pedal Travel Sensor, 14 Gear Position Sensor, 15 Paddle Shifter, 16 Clutch Pedal Travel Sensor, 21 Display Device, 22 Accelerator Pedal, 23 Brake Pedal, 24 Simulated H-Type Shifter, 25 Simulated Handle Shifter, 26 Simulated Clutch Pedal, 27 In-Vehicle Speaker, 100 Electric Vehicle, 101 Control Device, 102 Processor, 103 Memory, 104 Program, 105 Data

Claims

1. An electric vehicle having an electric motor as a driving source, The electric vehicle is characterized by comprising: an accelerator pedal, used for driving the electric vehicle; A simulated shift operating member, which simulates an operating member used for shifting operations of a transmission vehicle; A display device, for displaying information to the driver; a vehicle speed sensor for measuring the speed of the electric vehicle; and a control device that controls the torque of the electric motor according to the operation of the accelerator pedal, The control device is configured to perform: switching the relationship between the torque of the electric motor and the opening degree of the accelerator pedal and the vehicle speed according to the operation of the simulated speed change operating member; causing the display device to display an indicator that changes continuously in conjunction with the driving wheel torque of the electric vehicle and the vehicle speed; and The timing at which the operation of the simulated shift operating member is recommended is notified to the driver through the indicator.

2. The electric vehicle according to claim 1, characterized in that: The indicator is an indicator that displays a bar whose length continuously changes.

3. The electric vehicle according to claim 2, characterized in that: The indicator is an indicator that displays a bar whose color changes continuously as its length changes.

4. The electric vehicle according to claim 1, characterized in that: The indicator is an indicator that displays a graph whose area changes continuously.

5. The electric vehicle according to any one of claims 1 to 4, characterized in that: The indicator is displayed on the instrument panel.

6. The electric vehicle according to claim 2, characterized in that: The control device changes the relationship between the drive wheel torque and the vehicle speed and the length of the bar according to the driver's selection.

7. The electric vehicle according to claim 6, characterized in that: The control device has, as display modes of the bar, a first mode and a second mode for changing the length of the bar so that the bar reaches a maximum length in a region of higher rotation than in the first mode.

8. The electric vehicle according to claim 6, characterized in that: The control device has, as display modes of the bar, a first mode and a third mode for changing the length of the bar so that the bar reaches a maximum length in a region of lower torque and lower rotation than in the first mode.

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