Electric automobile

Abstract

To provide an electric automobile allowing a driver to experience operation of a manual shift-type internal combustion engine vehicle, and capable of replicating engine braking even while a charging acceptance amount of an on-vehicle battery is small.SOLUTION: The present disclosure relates to an electric automobile including an electric motor as a driving source. The electric automobile includes: a driving operation member used for driving the electric automobile; a pseudo shift operation member imitating an operation member used for shift operation of a manual shift-type internal combustion engine vehicle; a control device for controlling the electric automobile according to operation of the driving operation member; and an on-vehicle battery charged with electrical energy generated when regenerative braking is actuated. When a selection is made by a driver, the control device executes a control mode in which operation of the pseudo shift operation member is associated with torque of the electric motor. In addition, during execution of the control mode, the control device notifies the driver of a shift position according to a charging acceptance amount of the on-vehicle battery.SELECTED DRAWING: Figure 8

Description

[Technical field]

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

[0002] Patent Publication No. 6,787,507 discloses prior art relating to an electric vehicle that can simulate the manual gear shifting operation of a vehicle equipped with a manual transmission powered by an internal combustion engine (hereinafter referred to as a manual gear shifting internal combustion engine vehicle) by controlling an electric motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6787507 Summary of the Invention [Problem to be solved by the invention]

[0004] Engine braking is a braking method specific to manual-speed internal combustion engine vehicles. According to the above-mentioned conventional technology, it is possible to experience the operation of a manual-speed internal combustion engine vehicle with an electric vehicle. However, although there has been progress in studies on reproducing clutch operation and shift operation, there has been little progress in studies on reproducing engine braking without losing the operational feeling of operating an actual manual-speed internal combustion engine vehicle. [Means for solving the problem]

[0005] The present disclosure relates to an electric vehicle having an electric motor as a drive source. The electric vehicle is A driving operation member used for driving the electric vehicle; A pseudo speed change operation member that imitates an operation member used for speed change operation of a manually-shifted internal combustion engine vehicle; a control device that controls the electric vehicle in response to an operation of a driving operation member; and an on-board battery that charges the vehicle with electrical energy generated when regenerative braking is activated. The control device includes: Executing a control mode in which operation of the pseudo speed-change operating member is related to torque of the electric motor, as selected by a driver; When the above control modes are executed, Determining a virtual shift position based on operation of a pseudo gear shift operating member; activating a regenerative brake of a strength corresponding to a virtual shift position when the electric vehicle is traveling and there is no accelerator operation input; and notifying the driver of the shift position according to the charge acceptance level of the vehicle battery. Effect of the Invention

[0006] According to the electric vehicle of the present disclosure, engine braking of a manual-speed internal combustion engine vehicle is reproduced by regenerative braking. Regenerative braking may be limited by the charge capacity of the on-board battery, but in such a case, the driver is notified of the shift position according to the charge capacity, and the driver can adjust the shift position to reproduce engine braking even when the amount of regenerative power that can be accepted is low. For the driver, it is possible to continue driving the electric vehicle without losing the operating feel of a manual-speed internal combustion engine vehicle that is close to the real thing, and the driver's satisfaction can be increased. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating a configuration of an electric vehicle according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a tree diagram showing an example of electric vehicle control modes selectable by the control device. [Diagram 3] FIG. 2 is a tree diagram showing an example of electric vehicle control modes selectable by the control device. [Figure 4] FIG. 2 is a diagram showing the configuration of a control device related to driving control of an electric vehicle. [Diagram 5]FIG. 2 is a diagram showing the configuration of a control device related to sound control of an electric vehicle. [Figure 6] FIG. 2 is a diagram showing a configuration of a control device related to virtual engine braking. [Figure 7] FIG. 11 is a conceptual diagram for explaining notification to a driver regarding a shift position. [Figure 8] FIG. 4 is a flow chart showing a first example of processing by the control device related to notification to the driver. [Figure 9] FIG. 11 is a flow diagram showing a second example of the process of the control device related to notification to the driver. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0009] 1. Electric vehicle power system configuration 1 is a diagram illustrating a schematic configuration of an electric vehicle 100 according to an embodiment of the present disclosure. First, the configuration of the power system of the electric vehicle 100 will be described with reference to FIG.

[0010] The electric vehicle 100 is equipped with two electric motors (M) 4F, 4R at the front and rear. The electric motors 4F, 4R have the function of converting supplied electric power into torque and the function of converting input torque into electric power. The electric motors 4F, 4R are, for example, three-phase AC motors. The front electric motor 4F is connected to a front drive shaft 5F that drives the front wheels 6F. The rear electric motor 4R is connected to a rear drive shaft 5R that drives the rear wheels 6R. The front wheels 6F are suspended by independent left and right electronically controlled front suspensions 7F. The rear wheels 6R are suspended by independent left and right electronically controlled rear suspensions 7R.

[0011] The electric motors 4F, 4R are used as a power source for traveling. The front electric motor 4F and the rear electric motor 4R are respectively equipped with inverters (INV) 3F, 3R. The front inverter 3F and the rear inverter 3R are respectively connected to a battery (BATT) 2. The battery 2 stores electric energy for driving the electric motors 4F, 4R. In other words, the electric vehicle 100 is a battery electric vehicle (BEV) that runs on the electric energy stored in the battery 2. The inverters 3F, 3R are, for example, voltage-type inverters, and control the torque of the electric motors 4F, 4R by PWM control.

[0012] The front electric motor 4F and the rear electric motor 4R also function as generators that generate regenerative power from torque input from the front drive shaft 5F and the rear drive shaft 5R, respectively. By operating the electric motors 4F, 4R as generators while the electric vehicle 100 is traveling, the electric vehicle 100 can be decelerated by regenerative braking. At this time, the regenerative power generated by the electric motors 4F, 4R is charged to the battery 2 via the inverters 3F, 3R.

[0013] In the above description, the drive electric motors 4F, 4R are described as also functioning as generators, but the electric vehicle 100 may also be provided with drive electric motors and generators arranged separately from the drive electric motors at the front and rear.

[0014] 2. Electric vehicle control system configuration Next, the configuration of the control system of the electric vehicle 100 will be described with reference to FIG.

[0015] The electric vehicle 100 is equipped with a battery management system (BMS) 10. The battery management system 10 is a device that monitors the cell voltage, current, temperature, etc. of the battery 2. The battery management system 10 has a function of estimating the state of charge (SOC) of the battery 2. The functions of the battery management system 10 also include a function of estimating the charge acceptance amount of the battery 2, that is, the amount obtained by subtracting the current charge amount from the full charge amount.

[0016] The electric vehicle 100 is equipped with a vehicle speed sensor 11. At least one of wheel speed sensors (not shown) provided on each of the left and right front wheels 6F and the left and right rear wheels 6R is used as the vehicle speed sensor 11. The electric vehicle 100 is also equipped with an accelerator pedal stroke sensor 12. The accelerator pedal stroke sensor 12 is provided on an accelerator pedal 22, and outputs a signal indicating the amount of depression of the accelerator pedal 22, i.e., the accelerator opening. The electric vehicle 100 is also equipped with a brake pedal stroke sensor 13. The brake pedal stroke sensor 13 is provided on a brake pedal 23, and outputs a signal indicating the amount of depression of the brake pedal 23, i.e., the brake opening.

[0017] The accelerator pedal 22 and the brake pedal 23 are driving operation members used to drive the electric vehicle 100. In addition to these driving operation members, the electric vehicle 100 is equipped with pseudo gear shift operation members that imitate operation members used to change gears in a manually-shifted internal combustion engine vehicle. The pseudo gear shift operation members include a pseudo H-type shifter 24, a pseudo paddle shifter 25, and a pseudo clutch pedal 26 described below.

[0018] The pseudo-H-shaped shifter 24 is a dummy that is different from an actual H-shaped shifter. The pseudo-H-shaped shifter 24 has a structure similar to a shift stick provided in a console, and can be moved between shift positions along an H-shaped gate. However, since the electric vehicle 100 does not have an actual transmission, the shift positions of the pseudo-H-shaped shifter 24 are virtual shift positions. The pseudo-H-shaped shifter 24 is provided with a shift position sensor 14. The shift position sensor 14 outputs a signal indicating the shift position selected by the pseudo-H-shaped shifter 24.

[0019] The pseudo paddle shifter 25 is a dummy that is different from a real paddle shifter, which is a type of sequential shifter. The pseudo paddle shifter 25 has a structure similar to a shift paddle attached to a steering wheel, and the left and right paddles can be moved independently. The pseudo paddle 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 outputs a downshift signal when the left paddle is pulled.

[0020] The pseudo clutch pedal 26 is a dummy that is different from an actual clutch pedal. The pseudo clutch pedal 26 has a structure similar to a clutch pedal equipped in a conventional manual-speed internal combustion engine vehicle. For example, the pseudo clutch pedal 26 is equipped with a reaction 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 26, and the position when the pseudo clutch pedal 26 is depressed to the deepest is the end position of the pseudo clutch pedal 26. The driver can operate the pseudo clutch pedal 26 from the start end position to the end position against the reaction force from the reaction force mechanism. The pseudo clutch pedal 26 is equipped with a clutch pedal stroke sensor 16. The clutch pedal stroke sensor 16 outputs a signal indicating the depression amount of the pseudo clutch pedal 26. Since the electric vehicle 100 does not have an actual clutch, the operation amount of the pseudo clutch pedal 26, i.e., the clutch opening degree, is a virtual clutch opening degree.

[0021] Although the pseudo clutch pedal 26 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 of various structures as long as the driver can operate it from the start position to the end position against a reaction force and can experience the same operating sensation by foot or hand as the clutch pedal provided in a conventional manually variable-speed internal combustion engine vehicle.

[0022] The electric vehicle 100 also includes a human-machine interface (HMI) 20 as an interface with the driver, and an in-vehicle speaker 21. The HMI 20 includes a touch panel display. The HMI 20 displays information on the touch panel display, and receives input from the driver via touch operation on the touch panel display. The in-vehicle speaker 21 provides information to the driver by voice, and is also capable of outputting a pseudo engine sound, which will be described later.

[0023] The electric vehicle 100 is equipped with a control device 101. Sensors and devices to be controlled mounted on the electric vehicle 100 are connected to the control device 101 via an in-vehicle network. In addition to the battery management system 10, vehicle speed sensor 11, accelerator pedal stroke sensor 12, brake pedal stroke sensor 13, shift position sensor 14, paddle shift switch 15, and clutch pedal stroke sensor 16, the electric vehicle 100 is also equipped with various other sensors.

[0024] 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 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 related to the program. The program 104 is composed of multiple instructions. The processor 102 reads out and executes the program 104 and data 105 from the memory 103, and generates control signals based on signals acquired from each sensor. The number of processors 102 included in the control device 101 may be one or more.

[0025] The control device 101 can control the electric vehicle 100 in various control modes. The driver can select the control mode by touching the touch panel display of the HMI 20. In more detail, by touching the touch panel display of the HMI 20, one or more programs 104 associated with each touch operation are read from the memory 103 and executed by the processor 102. The control modes of the electric vehicle 100 by the control device 101 that can be selected by the driver by operating the HMI 20 will be described below.

[0026] 3. Electric vehicle control mode 2 and 3 are tree diagrams showing an example of control modes of the electric vehicle 100 that can be selected by the control device 101. In the HMI 20, a selection screen is displayed on the touch panel display according to the control tree shown in FIG.

[0027] An option "control mode" OP000 is displayed on the initial screen of the HMI 20. By selecting the option "control mode" OP000, an option "automatic mode" OP110 and an option "manual mode" OP120 are displayed on the touch panel display. When the option "automatic mode" OP110 is selected, the control mode of the electric vehicle 100 switches to the automatic mode. The automatic mode is a control mode for driving the electric vehicle 100 as a normal BEV. In the automatic mode, the driver can basically drive the electric vehicle 100 only by operating the accelerator pedal 22, the brake pedal 23, and the steering wheel (not shown). In the automatic mode, the shift operation of the pseudo H-type shifter 24, the shift operation of the pseudo paddle shifter 25, and the clutch operation of the pseudo clutch pedal 26 are disabled.

[0028] When the option "manual mode" OP120 is selected, the control mode of the electric vehicle 100 switches to the manual mode. The manual mode is a control mode for operating the electric vehicle 100 like a manually-shifted internal combustion engine vehicle. By selecting the option "manual mode" OP120, the following options are displayed on the touch panel display: "shift mode" OP210, "engine characteristics" OP220, "engine sound" OP230, "drive mode" OP240, and "suspension characteristics" OP250. By appropriately combining these options OP210-OP250, the driver can determine the characteristics of a manually-shifted internal combustion engine vehicle that he or she wants the electric vehicle 100 to emulate.

[0029] The option "shift mode" OP210 is an option for selecting a shift mode of the manual transmission when the electric vehicle 100 is operated like a manually-shifted internal combustion engine vehicle. As shown in FIG. 2, by selecting the option "shift mode" OP210, an option "paddle shift" OP311 and an option "stick shift" OP312 are displayed on the touch panel display. When the option "paddle shift" OP311 is selected, the shift mode of the manual transmission reproduced in the electric vehicle 100 is switched to the paddle shift mode. The paddle shift mode is a mode in which the pseudo paddle shifter 25 is used for shifting. In the paddle shift mode, the shift operation of the pseudo H-type shifter 24 is disabled. In the paddle shift mode, the operation when the gear ratio of the manual transmission is changed is reproduced by the shift operation of the pseudo paddle shifter 25. Note that the clutch operation in a real paddle shift type manual transmission is automatically performed by the robot. Therefore, in the paddle shift mode, the clutch operation of the pseudo clutch pedal 26 is not required. In the paddle shift mode, the clutch operation of the pseudo clutch pedal 26 is disabled.

[0030] When the option "stick shift" OP312 is selected, the stick shift mode is selected. The stick shift mode is a mode in which the pseudo H-type shifter 24 is used for shifting. In the stick shift mode, the shift operation of the pseudo paddle shifter 25 is disabled. In the stick shift mode, the operation when the gear ratio of the manual transmission is changed is reproduced by the shift operation of the pseudo H-type shifter 24. In the real H-type shifter type manual transmission, there are those in which the driver performs the clutch operation himself and those in which the clutch operation is left to a robot. When the option "stick shift" OP312 is selected, the touch panel display displays the options "with clutch operation" OP411 and "without clutch operation" OP412. When the option "with clutch operation" OP411 is selected, the stick shift mode is switched to a mode that requires the clutch operation of the pseudo clutch pedal 26. On the other hand, when the option "without clutch operation" OP412 is selected, the clutch operation of the pseudo clutch pedal 26 is disabled and the stick shift mode is switched to a mode that does not require the clutch operation.

[0031] The option "engine characteristics" OP220 is an option for selecting the characteristics of the internal combustion engine when the electric vehicle 100 is operated like a manually-shifted internal combustion engine vehicle. As shown in FIG. 2, by selecting the option "engine characteristics" OP220, an option "low-medium revolution type" OP321, an option "high revolution type" OP322, and an option "all-range type" OP323 are displayed on the touch panel display. When the option "low-medium revolution type" OP321 is selected, the characteristics of the internal combustion engine reproduced in the electric vehicle 100 are switched to a low-medium revolution type in which the torque in the low-medium revolution range is relatively high. When the option "high revolution type" OP322 is selected, the characteristics of the internal combustion engine reproduced in the electric vehicle 100 are switched to a high revolution type in which the torque in the high revolution range is relatively high. And when the option "all-range type" OP323 is selected, the characteristics of the internal combustion engine reproduced in the electric vehicle 100 are switched to an all-range type in which the torque is uniform over the entire range. However, the low to medium revolution type, the high revolution type, and the full range type are merely examples of engine characteristics that can be reproduced by controlling the electric vehicle 100.

[0032] The option "engine sound" OP230 is an option for selecting an engine sound to be reproduced in the electric vehicle 100. As shown in FIG. 2, by selecting the option "engine sound" OP230, the options "inline 4 supercharged engine" OP331, "flat 6 engine" OP332, and "V12 engine" OP333 are displayed on the touch panel display. When the option "inline 4 supercharged engine" OP331 is selected, the engine sound reproduced in the electric vehicle 100 is switched to the engine sound of an inline 4 supercharged engine. When the option "flat 6 engine" OP332 is selected, the engine sound reproduced in the electric vehicle 100 is switched to the engine sound of a flat 6 engine. And, when the option "V12 engine" OP333 is selected, the engine sound reproduced in the electric vehicle 100 is switched to the engine sound of a V12 engine. However, the inline 4 supercharged engine, the flat 6 engine, and the V12 engine are only examples of engine sounds that can be reproduced in the electric vehicle 100.

[0033] The option "drive mode" OP240 is an option for selecting the drive mode of the electric vehicle 100. As shown in FIG. 3, by selecting the option "drive mode" OP240, an option "four-wheel drive" OP341 and an option "rear-wheel drive" OP342 are displayed on the touch panel display. When the option "four-wheel drive" OP341 is selected, the drive mode of the electric vehicle 100 is switched to the four-wheel drive mode. In the four-wheel drive mode, the front wheels 6F are driven by the front electric motor 4F, and the rear wheels 6R are driven by the rear electric motor 4R. The torque distribution between the front wheels 6F and the rear wheels 6R can be fixed or variable by the control of the electric motors 4F, 4F by the inverters 3F, 3R. When the option "rear-wheel drive" OP342 is selected, the drive mode of the electric vehicle 100 is switched to the rear-wheel drive mode. In the rear-wheel drive mode, only the rear wheels 6R are driven by the rear electric motor 4R. However, in the electric vehicle 100, instead of or in addition to the rear-wheel drive mode, a front-wheel drive mode in which only the front wheels 6F are driven by the front electric motor 4F can also be selected.

[0034] The option "suspension characteristics" OP250 is an option for selecting the suspension characteristics of the electric vehicle 100. As shown in FIG. 3, by selecting the option "suspension characteristics" OP250, an option "soft" OP351, an option "hard" OP352, and an option "medium" OP353 are displayed on the touch panel display. When the option "soft" OP351 is selected, the suspension characteristics of the electric vehicle 100 are switched to the soft mode. In the soft mode, the damping force of the suspensions 7F and 7R is made low. When the option "hard" OP352 is selected, the suspension characteristics of the electric vehicle 100 are switched to the hard mode. In the hard mode, the damping force of the suspensions 7F and 7R is made high. And when the option "medium" OP353 is selected, the suspension characteristics of the electric vehicle 100 are switched to the medium mode. In the medium mode, the damping force of the suspensions 7F and 7R is made intermediate between the soft mode and the hard mode. However, since the suspensions 7F and 7R are electronically controlled, the suspension characteristics can be adjusted widely. Therefore, the soft mode, hard mode, and medium mode are merely examples of suspension characteristics that can be realized in the electric vehicle 100. Note that the drive mode and suspension characteristics may be selectable not only in the manual mode but also in the automatic mode.

[0035] By operating the touch panel display of the HMI 20 according to the control tree described above, the control mode of the electric vehicle 100 can be switched to suit the driver's preference. The switchable control modes include a mode related to the driving control of the electric vehicle 100 and a mode related to the sound control of the electric vehicle 100. Specifically, the mode related to the option "engine sound" OP230 is the mode related to sound control, and the other modes are the modes related to driving control. In the following chapters, the driving control and sound control of the electric vehicle 100 by the control device 101 will be described.

[0036] 4. Electric vehicle driving control Fig. 4 is a diagram showing the configuration of the control device 101 related to the driving control of the electric vehicle 100. In detail, Fig. 2 shows the configuration particularly related to torque control among driving control. One or more driving control programs 104 stored in the memory 103 are executed by the processor 102, whereby the processor 102 functions as a driving control device.

[0037] A control mode signal is input from the HMI 20 to the control device 101 as a driving control device. The control mode signal includes information about the control mode selected by the driver. The control device 101 executes process P110 based on the control mode signal. In process P110, the control mode is switched in accordance with the control mode signal. The control mode switching that particularly affects driving control is switching between automatic mode and manual mode.

[0038] When the control mode is switched to the automatic mode, the control device 101 executes a process P120 for torque calculation in the automatic mode. In the process P120, the control device 101 obtains the vehicle speed from the signal of the vehicle speed sensor 11, and obtains the accelerator opening from the signal of the accelerator pedal stroke sensor 12. The control device 101 has a motor torque map with the accelerator opening and the vehicle speed as parameters. The control device 101 inputs the vehicle speed and the accelerator opening into the motor torque map, and controls the inverters 3F, 3R to generate the torque obtained from the motor torque map in the electric motors 4F, 4R.

[0039] When the control mode is switched to the manual mode, the control device 101 executes a process P130 for torque calculation in the manual mode. The process P130 includes a process P131 for calculating the torque to be generated at the drive wheels. The process P130 also includes a process P132 and a process P133. The process P132 is a process for calculating the torque to be generated at the front electric motor 4F, and the process P133 is a process for calculating the torque to be generated at the rear electric motor 4R. The process P132 and the process P133 are executed according to the drive wheel torque calculated in the process P130 and the torque distribution between the front wheels 6F and the rear wheels 6R.

[0040] A vehicle model MOD01 is used for calculating 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. An engine virtually realized by the vehicle model MOD01 is called a virtual engine, a clutch virtually realized is called a virtual clutch, and a transmission virtually realized is called a virtual transmission. A virtual engine is modeled in the engine model MOD11. A virtual clutch is modeled in the clutch model MOD12. A virtual transmission is modeled in the transmission model MOD13.

[0041] The engine model MOD11 calculates a virtual engine speed and a virtual engine torque. The virtual engine speed is calculated from the vehicle speed, the total reduction ratio, and the slip ratio of the virtual clutch. The virtual engine torque is calculated from the virtual engine speed and the accelerator opening. The vehicle speed is obtained from a signal of the vehicle speed sensor 11. The accelerator opening is obtained from a signal of the accelerator pedal stroke sensor 12. The total reduction ratio is a numerical value obtained by multiplying the speed ratio of the virtual transmission by a reduction ratio determined by the mechanical structure from the virtual transmission to the driving wheels. In the engine model MOD11, the relationship between the virtual engine speed and the virtual engine torque is specified for each accelerator opening. The engine characteristics of the engine model MOD11 can be selected by the driver by operating the HMI 20. In the example shown in FIG. 2, the engine characteristics can be selected from a low-medium rotation type, a high rotation type, and a full-range type.

[0042] The clutch model MOD12 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 clutch opening. When the stick shift mode with clutch operation is selected as the shift mode, the clutch opening is acquired from a signal of the clutch pedal stroke sensor 16. The clutch opening is 0% at the start position of the pseudo clutch pedal 26 and 100% at the end position of the pseudo clutch pedal 26. In the clutch model MOD12, a torque transmission gain is given with respect to the clutch opening. The torque transmission gain is converted into the clutch torque capacity of the virtual clutch, that is, the 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 MOD11, a virtual clutch torque input from the virtual clutch to the virtual transmission is calculated. In addition, in the clutch model MOD12, a value obtained by subtracting the torque transmission gain from 1 is calculated as a slip ratio. The slip ratio is used to calculate the virtual engine speed in the engine model MOD11.

[0043] When the paddle shift mode is selected as the shift mode, the clutch opening degree input to the clutch model MOD12 is calculated using the clutch operation model. Also, when the clutch operation-less stick shift mode is selected as the shift mode, the clutch opening degree input to the clutch model MOD12 is calculated using the clutch operation model. The clutch operation model is a model that simulates the clutch operation of an exemplary driver. When the paddle shift mode is selected, the vehicle speed, virtual engine speed, and a signal from the paddle shift switch 15 are input to the clutch operation model. When the clutch operation-less stick shift mode is selected, the vehicle speed, virtual engine speed, and a signal from the shift position sensor 14 are input to the clutch operation model.

[0044] The signals from the paddle shift switch 15 and the shift position sensor 14 are used to time the clutch operation. When the driver's shift operation is detected by the signals from the paddle shift switch 15 and the shift position sensor 14, the clutch opening is maximized in the clutch operation model so as to disengage the virtual clutch. The vehicle speed and the virtual engine speed are used to calculate the clutch opening. In the clutch operation model, the clutch opening is calculated based on the rotational speed difference between the rotational speed of the input shaft of the virtual transmission calculated from the vehicle speed and the virtual engine speed so as to smoothly match the virtual engine speed.

[0045] The transmission model MOD13 calculates a virtual gear ratio. The virtual gear ratio is a gear ratio in a virtual transmission that is determined by a virtual shift position. The virtual gear ratio is set for each shift position. The maximum virtual gear ratio is set for first gear, and the virtual gear ratios become smaller in the order of second gear, third gear, fourth gear, .... In the stick shift mode, the shift positions are in one-to-one correspondence with the signal of the shift position sensor 14. In the paddle shift mode, the shift position is increased by one step in response to an upshift signal from the paddle shift switch 15, and decreased by one step in response to a downshift signal from the paddle shift switch 15. Note that while the number of shift positions is physically determined in the pseudo H-type shifter 24, there are no physical restrictions on the number of shift positions in the pseudo paddle shifter 25. Therefore, the transmission model MOD13 may be different between the stick shift mode and the paddle shift mode, and the number of shift positions in the paddle shift mode may be greater than the number of shift positions in the stick shift mode.

[0046] The transmission model MOD13 calculates a virtual transmission torque using the virtual gear ratio and the virtual clutch torque. The virtual transmission torque is a virtual torque output from the virtual transmission. The control device 101 controls the inverters 3F, 3R so as to change the output torque of the electric motors 4F, 4R in response to the virtual transmission torque. The virtual transmission torque changes discontinuously in response to switching of the virtual gear ratio. This discontinuous change in the virtual transmission torque generates a torque shock in the electric vehicle 100, creating the impression that the vehicle is equipped with a stepped transmission.

[0047] The vehicle model MOD01 calculates the drive wheel torque from the virtual transmission torque and the reduction ratio. When the four-wheel drive mode is selected as the drive mode, 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 to the front wheels 6F and the rear wheels 6R can be fixed or can be changed actively or passively. When the rear-wheel drive mode is selected as the drive mode, the drive wheel torque is the sum of the torques acting on the left and right rear wheels 6R.

[0048] In process P132, the torque of the front electric motor 4F in the manual 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.

[0049] In process P133, the torque of the rear electric motor 4R in the manual 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 as to cause the rear electric motor 4R to generate the rear motor torque calculated in process P133.

[0050] In the configuration shown in Fig. 2, the battery management system 10 and the brake pedal stroke sensor 13 are not necessarily required for the above-mentioned driving control. However, if switching of the control mode affects the SOC of the battery 2, the signal of the battery management system 10 may be used as information for determining whether or not to switch the control mode. Also, in a case where the operation method of the electric vehicle 100 changes significantly, such as switching between the automatic mode and the manual mode, the condition for switching may be that the brake pedal 23 is depressed. In that case, the signal of the brake pedal stroke sensor 13 can be used as information for determining that the brake pedal 23 is depressed.

[0051] 5. Sound control for electric vehicles 5 is a diagram showing the configuration of a control device 101 related to sound control of an electric vehicle 100. One or more sound control programs 104 stored in a memory 103 are executed by the processor 102, causing the processor 102 to function as a sound control device. The processor 102 functioning as a torque control device and the processor 102 functioning as a sound control device may be separate processors or may be the same processor.

[0052] The control device 101 as a sound control device can generate artificially generated sounds from the in-vehicle speaker 21. One of the artificial sounds is a pseudo engine sound that resembles the engine sound of a conventional internal combustion engine vehicle. When a control mode signal indicating that the manual mode has been selected is input from the HMI 20, the control device 101 as a sound control device executes process P140. In process P140, a pseudo engine sound is generated based on the virtual engine torque and virtual engine speed calculated in process P131.

[0053] In process P140, the engine sound selected by the HMI 20 is used as the sound source of the pseudo engine sound generated from the in-vehicle speaker 21. In the example shown in FIG. 2, an engine sound selected from an in-line 4-cylinder supercharged engine, a flat 6-cylinder engine, and a V12 engine is used as the sound source of the pseudo engine sound. However, in process P140, the sound of the sound source is not used as is. In process P140, the sound pressure of the sound source is changed, for example, by an amplifier, and the frequency of the sound source is changed, for example, by a frequency modulator.

[0054] The process P140 includes a process P141 for calculating the engine sound pressure and a process P142 for calculating the engine sound frequency. In the process P141, the sound pressure of the pseudo engine sound is calculated from the virtual engine torque using a sound pressure map M11. The sound pressure map M11 is created so that the sound pressure increases as the virtual engine torque increases. In the process P142, the frequency of the pseudo engine sound is calculated from the virtual engine speed using a frequency map M12. The frequency map M12 is created so that the frequency increases as the virtual engine speed increases. The virtual engine torque and the virtual engine speed change depending on the accelerator operation, the shift operation, and the clutch operation of the driver. By changing the sound pressure and the frequency of the pseudo engine sound according to the changing virtual engine torque and the virtual engine speed, the driver can be given a sense of reality as if he or she were driving a real manual transmission internal combustion engine vehicle.

[0055] 6. Reproducing engine braking with regenerative braking 6-1. Overview The driver of electric vehicle 100 can experience the operation of a manual transmission internal combustion engine vehicle in electric vehicle 100 by switching the control mode to the manual mode by operating HMI 20. While the control mode is set to the manual mode, electric vehicle 100 is controlled to reproduce the behavior of a manual transmission internal combustion engine vehicle.

[0056] One of the behaviors unique to manual transmission internal combustion engine vehicles is engine braking. When the electric vehicle 100 is in manual mode, the operation of the engine brake is also reproduced. However, since the electric vehicle 100 does not have an actual transmission, the engine brake that operates in manual mode is a virtual engine brake that is simulated by regenerative braking. Hereinafter, the engine brake that is virtually realized by regenerative braking will be referred to as a virtual engine brake.

[0057] 6 is a diagram showing processing related to the operation of the virtual engine brake by the control device 101. The processing related to the operation of the virtual engine brake includes a process P151 for determining whether or not the virtual engine brake is being operated, and a process P152 for operating the regenerative brake. These processes are performed by the control device 101 as a driving control device.

[0058] In process P151, a determination is made as to whether or not to activate the engine brake. When the electric vehicle 100 is traveling with the manual mode selected and there is no accelerator operation input, the control device 101 activates the virtual engine brake. Whether or not the manual mode is selected is acquired from a control mode signal input from the HMI 20. Whether or not there is an accelerator operation input, that is, whether or not the accelerator pedal 22 is depressed by the driver, is acquired from a signal from the accelerator pedal stroke sensor 12. Whether or not the electric vehicle 100 is traveling can be acquired from a signal from the vehicle speed sensor 11, and it is determined that the electric vehicle 100 is traveling when the vehicle speed is not 0. Based on the signals acquired from the HMI 20, the vehicle speed sensor 11, and the accelerator pedal stroke sensor 12, the control device 101 determines to activate the virtual engine brake when the electric vehicle 100 is traveling in the manual mode and the accelerator pedal 22 is not depressed.

[0059] When it is determined that the virtual engine brake is to be activated, the control device 101 executes process P152. In process P152, the electric motors 4F, 4R are controlled so as to convert the torque input from the front drive shaft 5F and the rear drive shaft 5R into regenerative power to apply regenerative braking. The strength of the regenerative braking is determined according to the virtual shift position. By activating the regenerative braking, the engine braking of a manually-shifted internal combustion engine vehicle is reproduced.

[0060] By reproducing engine braking in this manner, the behavior of the electric vehicle 100 can be made closer to that of a real manual transmission internal combustion engine vehicle. However, unlike engine braking in a real manual transmission internal combustion engine vehicle, the use of regenerative braking may be limited depending on the state of the battery 2. Specifically, when the charge acceptance capacity of the battery 2 is insufficient, there is nowhere to charge the regenerative power generated by the regenerative braking, so the use of the regenerative braking is limited.

[0061] Here, the larger the gear ratio, the stronger the engine brake works. Even in the manual mode of the electric vehicle 100, in order to reproduce engine brake, the larger the virtual gear ratio, the stronger the regenerative brake is operated. In other words, if the virtual gear ratio is small, it is possible to reproduce engine brake without strongly operating the regenerative brake. The virtual gear ratio increases as the virtual shift position moves to the downshift side. Therefore, the electric vehicle 100 notifies the driver of the virtual shift position when there is a shortage of charge acceptance amount or when it is predicted that there will be a shortage in the manual mode. The notification to the driver will be explained below with a specific example. Note that the following explanation will be given assuming that the virtual shift position consists of six gears from 1st gear to 6th gear, but the same notification is also given when the number of shift positions of the virtual shift position is more or less than that.

[0062] 6-2. Virtual engine brake usage scenarios FIG. 7 shows a scene in which the electric vehicle 100 is traveling on a mountain road 200 with a continuous downward slope, as an example of a situation in which virtual engine braking is expected to be used frequently.

[0063] At the time (a) when the electric vehicle 100 approaches the mountain road 200, the charge acceptance amount of the battery 2 is sufficiently high. When the electric vehicle 100 enters the mountain road 200, the driver shifts down the virtual shift position and starts to operate the virtual engine brake in order to reduce the use of the brake pedal 23.

[0064] For a while after starting to travel along the mountain road 200, the charge acceptance is sufficient and virtual engine braking can be used regardless of the position of the virtual shift position. During this time, the driver is not notified of the shift position. Alternatively, the driver is notified that all shift positions are selectable.

[0065] As the virtual engine is used, the charging of battery 2 progresses, and at the point (b) the charge acceptance amount begins to be insufficient to use virtual engine braking in first gear. When this happens, the driver is notified to select a shift position that is upshift from first gear, i.e., second gear or higher. If the driver follows the notification and shifts to second gear or higher, virtual engine braking can continue to be used.

[0066] If the charging of battery 2 further progresses and the charge acceptance decreases, and the charge acceptance becomes insufficient to use virtual engine braking in second gear, a notification is then sent to the driver urging him to select a shift position of third gear or higher. If the driver follows the notification and changes the shift position to third gear or higher, virtual engine braking can continue to be used.

[0067] As the charging of the battery 2 progresses and the charge acceptance amount decreases, a notification is given to the driver to select a shift position according to the charge acceptance amount.

[0068] 6-3. First example of processing Fig. 8 is a flow diagram showing an example of processing performed by the control device 101. The series of processing shown in Fig. 8 is repeatedly executed at a predetermined control period, for example, while the electric vehicle 100 is running. The series of processing is realized by the processor 102 executing the program 104.

[0069] According to the flow shown in Fig. 8, first, in step S101, it is determined whether or not the virtual engine brake is operating. If the virtual engine brake is not operating, the series of processes ends.

[0070] In step S101, the control device 101 may determine whether the electric vehicle 100 is in a virtual engine braking use scene, such as a scene in which the electric vehicle 100 is traveling on a mountain road with a continuous downhill slope, rather than whether the virtual engine brake is simply operating temporarily. A virtual engine braking use scene here is a scene in which the virtual engine brake is expected to be used continuously to a certain extent. The control device 101 may determine that the electric vehicle 100 is in a virtual engine braking use scene when the virtual engine brake is operating continuously for a predetermined period of time or more, or when the frequency at which the virtual engine brake is operating within a certain period of time is equal to or more than a predetermined frequency.

[0071] If the virtual engine brake is operating, step S102 is executed. In step S102, it is determined whether the charge acceptance amount of the battery 2 is less than a predetermined amount S1. The predetermined amount S1 is a lower limit of the charge acceptance amount at which the virtual engine brake can be operated even when the virtual shift position is first gear. The control device 101 acquires the charge acceptance amount from a signal input from the battery management system 10. If the charge acceptance amount is equal to or greater than the predetermined amount S1, the series of processes ends.

[0072] If the charge acceptance amount is less than the predetermined amount S1, step S103 is executed. In step S103, it is determined whether the charge acceptance amount is less than a predetermined amount S2. The predetermined amount S2 is the lower limit of the charge acceptance amount at which the virtual engine brake can be activated when the virtual shift position is second speed or higher. The predetermined amount S2 is an amount less than the predetermined amount S1.

[0073] If the charge acceptance amount is equal to or greater than the predetermined amount S2, step S104 is executed. In step S104, a notification is given to the driver to prompt the driver to select a second or higher gear shift position. The notification is given by the HMI 20 displaying selectable shift positions on the touch panel display. Alternatively, the notification may be given by voice via the in-vehicle speaker 21.

[0074] On the other hand, if the charge acceptance amount is less than the predetermined amount S2, step S105 is executed. In step S105, it is determined whether the charge acceptance amount is less than a predetermined amount S3. The predetermined amount S3 is the lower limit of the charge acceptance amount at which the virtual engine brake can be activated when the virtual shift position is 4th gear or higher. The predetermined amount S3 is an amount less than the predetermined amount S2.

[0075] If the charge acceptance amount is equal to or greater than the predetermined amount S3, step S106 is executed. In step S106, a notification is given to the driver to prompt him / her to select a fourth-speed or higher shift position. The notification is given by display or sound.

[0076] On the other hand, if the charge acceptance amount is less than the predetermined amount S3, step S107 is executed. In step S107, a notification is given to the driver to prompt the driver to shift the shift position to sixth gear. The notification is given by display or sound.

[0077] In this way, the electric vehicle 100 requests the driver to select a shift position according to the charge acceptance amount while deceleration is being performed by virtual engine braking in the manual mode. More specifically, the electric vehicle 100 determines whether the current charge acceptance amount is less than the threshold value for the charge acceptance amount set for each shift position. If the current charge acceptance amount is less than the threshold value set for any shift position, the driver is notified to select a shift position on the upshift side of the shift position. At this time, as in the above steps S104 and S106, if there are multiple selectable shift positions, the multiple shift positions are notified to the driver. Note that the threshold value for each shift position does not necessarily need to be set for all shift positions. In the above example, a case has been described in which a three-stage notification is made to prompt the driver to select a shift position of 2nd gear or higher, 4th gear or higher, or 6th gear. Alternatively, the notification of the selectable shift positions may be switched more finely than in the above example. In other words, in addition to the above notification, a notification to prompt the driver to select a shift position of 3rd gear or higher or a notification to prompt the driver to select a shift position of 5th gear or higher may be made.

[0078] Effects According to the above process, when the charge acceptance amount of the battery 2 decreases, a notification is given to the driver to urge him / her to keep the virtual shift position on the upshift side. By selecting the upshift side shift position, the strength and frequency of the virtual engine brake are reduced, and it is possible to reproduce the virtual engine brake even when the charge acceptance amount is low. In this way, even if the charge acceptance amount of the battery 2 decreases, it is possible to continue using the manual mode without losing the operating feel of a manual transmission internal combustion engine vehicle. This can increase the satisfaction of the driver who wants to experience the operation of a manual transmission internal combustion engine vehicle closer to the real thing. This is particularly effective in situations where it is expected that the amount of regenerative power will increase by using the virtual engine brake a lot, such as downhill.

[0079] 6-5. Second example of processing Fig. 9 is a flow diagram showing another example of processing performed by the control device 101. The series of processing shown in Fig. 9 is repeatedly executed at a predetermined control period, for example, while the electric vehicle 100 is running. The series of processing is realized by the processor 102 executing the program 104.

[0080] According to the flow shown in Fig. 9, first, in step S201, it is determined whether or not the virtual engine brake is operating. If the virtual engine brake is not operating, the series of processes ends.

[0081] In step S201, the control device 101 may determine whether or not the electric vehicle 100 is in a virtual engine braking use scene. In this case, if the electric vehicle 100 is not in a virtual engine braking use scene, the series of processes ends, and if the electric vehicle 100 is in a virtual engine braking use scene, the process proceeds to step S202.

[0082] If the virtual engine brake is operating, step S202 is executed. In step S202, it is determined whether the charge acceptance amount of the battery 2 is less than a predetermined amount. The predetermined amount here may be the same as the predetermined amount S1 in step S102, or may be less than that. If the charge acceptance amount is equal to or greater than the predetermined amount, the series of processes ends.

[0083] The determination in step S202 may be made based on the SOC, in which case the series of processes ends when the SOC is equal to or less than a predetermined ratio, and the process proceeds to step S203 when the SOC is greater than the predetermined ratio.

[0084] If the charge acceptance amount is less than the predetermined amount, step S203 is executed. In step S203, the control device 101 requests the driver not to downshift. For example, the control device 101 displays a message such as "Downshifting will be restricted" on the HMI 20.

[0085] In this way, the control device 101 may request the driver not to downshift when the charge acceptance amount becomes equal to or less than a predetermined amount. In this case, as in the first example, by maintaining the virtual shift position on the upshift side, the strength and frequency of the virtual engine brake are reduced, and it becomes possible to reproduce engine braking by regenerative braking at least when the charge acceptance amount is small. In this way, regardless of the charge acceptance amount, it is possible to maintain an operating feel as if the driver were operating an actual manual transmission internal combustion engine vehicle.

[0086] 6-6.Modifications In the flow of Fig. 9, multiple thresholds may be set for the charge acceptance amount, and a minimum shift position allowed may be set for each threshold. For example, for a first threshold of the charge acceptance amount, fourth gear may be set as the minimum shift position, and if the charge acceptance amount is less than the first threshold, a request may be made not to downshift to third gear or lower. Also, for a second threshold smaller than the first threshold, third gear may be set as the minimum shift position, and if the charge acceptance amount is less than the second threshold, a request may be made not to downshift to second gear or lower.

[0087] In step S202 of the flow in FIG. 9, it may be determined whether or not an abnormality has occurred in the battery 2. If no abnormality has occurred in the battery 2, the series of processes ends, and if an abnormality has occurred in the battery 2, the process proceeds to step S203. When an abnormality has occurred in the battery 2, the battery 2 may also be unable to accept regenerative power. Even in such a case, by urging the driver to keep the virtual shift position on the upshift side, it is possible to reduce the frequency of use of the virtual engine brake, and it is possible to maintain an operating feel similar to that of an actual manual-speed internal combustion engine vehicle.

[0088] Furthermore, the control device 101 may reduce the charge acceptance amount of the battery 2 in advance according to a prediction of the amount of regenerative power to be generated. For example, the control device 101 communicates with a navigation system to acquire in advance a route along which the electric vehicle 100 is scheduled to travel. If the route along which the electric vehicle 100 is scheduled to travel includes a route with a continuous downhill slope, the control device 101 may discharge the battery 2 to reduce the charge amount before the route along the continuous downhill slope is reached. [Explanation of symbols]

[0089] 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 stroke sensor, 13 brake pedal stroke sensor, 14 shift position sensor, 15 paddle shift switch, 16 clutch pedal stroke sensor, 21 in-vehicle speaker, 22 accelerator pedal, 23 brake pedal, 24 pseudo H-type shifter, 25 pseudo paddle shifter, 26 pseudo clutch pedal, 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 drive source, A driving operation member used for driving the electric vehicle; A pseudo speed change operation member that imitates an operation member used for speed change operation of a manually-shifted internal combustion engine vehicle; a control device that controls the electric vehicle in response to an operation of the driving operation member; an on-board battery that charges the electric energy generated when regenerative braking of the electric vehicle is activated; The control device includes: Executing a control mode in which operation of the pseudo speed-change operating member is related to torque of the electric motor, as selected by a driver; When the control mode is executed, determining a virtual shift position based on operation of the pseudo gear shift operating member; activating a regenerative brake of a strength corresponding to the virtual shift position when the electric vehicle is traveling and no accelerator operation is input; and notifying a driver of the electric vehicle of a shift position according to a charge acceptance amount of the on-board battery. An electric vehicle characterized by

2. 2. The electric vehicle according to claim 1, a threshold value of the charge acceptance amount is set for each of the virtual shift positions; The control device includes: During execution of the control mode, while a regenerative brake is being applied at a strength corresponding to the virtual shift position, determining whether the charge acceptance amount is less than the threshold value; and when the charge acceptance amount is less than a threshold value set for any one of the shift positions, notifying the driver of a shift position that is on an upshift side of the any one of the shift positions. An electric vehicle characterized by

3. 3. The electric vehicle according to claim 2, The control device is configured to notify the driver of a plurality of shift positions when the shift positions on the upshift side of any one of the shift positions include a plurality of shift positions. An electric vehicle characterized by

4. 2. The electric vehicle according to claim 1, The control device includes: During execution of the control mode, while a regenerative brake is being applied at a strength corresponding to the virtual shift position, determining whether or not the charge acceptance amount is less than a predetermined amount; and if the charge acceptance amount is less than the predetermined amount, requesting the driver not to downshift. An electric vehicle characterized by

5. 5. The electric vehicle according to claim 4, The control device includes: When the charging rate of the on-board battery is equal to or higher than a predetermined rate, or when an abnormality occurs in the on-board battery, it is determined that the charge acceptance amount is less than the predetermined amount. An electric vehicle characterized by

6. 6. The electric vehicle according to claim 1, The driving operation member includes an accelerator pedal, The pseudo speed change operation member is A pseudo H-type shifter simulating an H-type shifter of a manual transmission; and a pseudo clutch operating device that simulates a clutch operating device. An electric vehicle characterized by

7. 7. The electric vehicle according to claim 6, The control device is configured to change the torque of the electric motor in accordance with the shift position selected by the pseudo H-type shifter, the operation amount of the pseudo clutch operation device, and the operation amount of the accelerator pedal in the control mode. An electric vehicle characterized by

8. 6. The electric vehicle according to claim 1, The driving operation member includes an accelerator pedal, The pseudo speed change operation member includes a pseudo sequential shifter that simulates a sequential shifter of a manual transmission. An electric vehicle characterized by

9. 9. The electric vehicle according to claim 8, The control device is configured to change the torque of the electric motor in accordance with the shift position selected by the pseudo sequential shifter and the operation amount of the accelerator pedal in the control mode. An electric vehicle characterized by

10. 6. The electric vehicle according to claim 1, The driving operation member includes an accelerator pedal, The pseudo speed-change operation member includes a pseudo H-type shifter that simulates an H-type shifter of a manual transmission. An electric vehicle characterized by

11. 11. The electric vehicle according to claim 10, The control device is configured to change the torque of the electric motor in accordance with the shift position selected by the pseudo H-type shifter and the operation amount of the accelerator pedal in the control mode. An electric vehicle characterized by

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