Electric vehicle

Abstract

To reproduce the behavior of a manual shift type internal combustion engine vehicle at the time of fuel-cut in an electric vehicle capable of simulating the shift operation of the manual shift type internal combustion engine vehicle.SOLUTION: An electric vehicle according to an embodiment of the present disclosure includes: an accelerator pedal; a pseudo shifter imitating a shifter used for gear shift operation of a manual transmission type internal combustion engine vehicle; a pseudo tachometer imitating a tachometer of the manual transmission type internal combustion engine vehicle; and a display control device that changes a numerical value indicated by the pseudo tachometer. The display control device makes the numerical value indicated by the pseudo tachometer proportional to the vehicle speed of the electric vehicle, and changes a proportional relationship between the numerical value indicated by the pseudo tachometer and the vehicle speed according to a shift position selected by operation of the pseudo shifter. However, when the numerical value indicated by the pseudo tachometer reaches a first threshold value in a state where the accelerator pedal is depressed, the display control device gradually reduces the numerical value indicated by the pseudo tachometer without following the proportional relationship.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2022-030838 discloses an electric vehicle capable of pseudo-reproducing a manual shift operation of a vehicle equipped with a manual transmission having an internal combustion engine as a power source (hereinafter referred to as a manual shift type internal combustion engine vehicle) by controlling an electric motor. The electric vehicle disclosed in this publication is provided with a pseudo engine speed meter (hereinafter referred to as a pseudo tachometer). The virtual engine speed calculated based on the rotational speed of the wheels and the gear ratio is displayed on the pseudo tachometer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a manual shift type internal combustion engine vehicle, when the engine speed becomes excessive, fuel cut is performed to protect the internal combustion engine. There are changes in the behavior of the manual shift type internal combustion engine vehicle before and after the fuel cut. However, in the electric vehicle disclosed in the above publication, the behavior at the time of fuel cut of the manual shift type internal combustion engine vehicle has not been reproduced yet.

[0005] The present disclosure has been made in view of the above problems. One object of the present disclosure is to enable reproduction of the behavior at the time of fuel cut of a manual shift type internal combustion engine vehicle in an electric vehicle capable of simulating the shift operation of a manual shift type internal combustion engine vehicle.

Means for Solving the Problems

[0006] An electric vehicle according to an embodiment of the present disclosure is an electric vehicle having an electric motor as a drive source, and includes an accelerator pedal, a pseudo shifter imitating a shifter used for shifting operation of a manual transmission internal combustion engine vehicle, a pseudo tachometer imitating a tachometer of a manual transmission internal combustion engine vehicle, and a display control device for changing a numerical value indicated by the pseudo tachometer. The display control device makes the numerical value indicated by the pseudo tachometer proportional to the vehicle speed of the electric vehicle, and changes the proportional relationship between the numerical value indicated by the pseudo tachometer and the vehicle speed according to the shift position selected by the operation of the pseudo shifter. However, when the numerical value indicated by the pseudo tachometer reaches a first threshold value while the accelerator pedal is depressed, the display control device gradually decreases the numerical value indicated by the pseudo tachometer without following the above proportional relationship.

[0007] In one embodiment of the present disclosure, when the numerical value indicated by the pseudo tachometer decreases to a second threshold value lower than the first threshold value while the accelerator pedal is depressed, the display control device may change the numerical value indicated by the pseudo tachometer again according to the above proportional relationship. Also, when the accelerator pedal is released before the numerical value indicated by the pseudo tachometer decreases to the second threshold value, the display control device may change the numerical value indicated by the pseudo tachometer again according to the above proportional relationship.

[0008] The electric vehicle according to an embodiment of the present disclosure may further include a torque control device for controlling the torque of the electric motor. The torque control device changes the torque of the electric motor according to the opening degree of the accelerator pedal. However, when the numerical value indicated by the pseudo tachometer reaches the first threshold value, the torque control device may decrease the torque of the electric motor regardless of the opening degree of the accelerator pedal. Also, when the numerical value indicated by the pseudo tachometer decreases to a second threshold value lower than the first threshold value, the torque control device may change the torque again according to the opening degree of the accelerator pedal.

Advantages of the Invention

[0009] According to the above electric vehicle, when the value indicated by the pseudo tachometer reaches the first threshold value while the accelerator pedal is depressed, the value indicated by the pseudo tachometer gradually decreases regardless of the vehicle speed. This corresponds to the decrease in the engine rotation speed indicated by the tachometer when fuel cut is performed in a manual transmission internal combustion engine vehicle. That is, according to the above electric vehicle, the behavior during fuel cut of a manual transmission internal combustion engine vehicle can be reproduced.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0011] 1. Configuration of the power system of the electric vehicle FIG. 1 is a diagram schematically showing the configuration of an electric vehicle 100 according to an embodiment of the present disclosure. First, with reference to FIG. 1, the configuration of the power system of the electric vehicle 100 will be described.

[0012] The electric vehicle 100 is equipped with two electric motors (M) 4F and 4R at the front and rear as the driving power source. The electric motors 4F and 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 an electronically controlled front suspension 7F with independent left and right sides. The rear wheels 6R are suspended by an electronically controlled rear suspension 7R with independent left and right sides.

[0013] Inverters (INV) 3F and 3R are respectively attached to the front electric motor 4F and the rear electric motor 4R. The front inverter 3F and the rear inverter 3R are respectively connected to a battery (BATT) 2. That is, the electric vehicle 100 is a battery electric vehicle (BEV) that runs on the electric energy stored in the battery 2. The inverters 3F and 3R are, for example, voltage source inverters, and control the torque of the electric motors 4F and 4R by PWM control.

[0014] 2. Configuration of the control system of the electric vehicle Subsequently, the configuration of the control system of the electric vehicle 100 will be described with reference to FIG. 1.

[0015] The electric vehicle 100 is equipped with 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 is used as the vehicle speed sensor 11. In addition, the electric vehicle 100 is equipped with 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 depression amount of the accelerator pedal 22, that is, the accelerator opening. Furthermore, the electric vehicle 100 is equipped with 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 depression amount of the brake pedal 23, that is, the brake opening.

[0016] The accelerator pedal 22 and the brake pedal 23 are driving operation members used for driving the electric vehicle 100. Apart from these driving operation members, the electric vehicle 100 is provided with a pseudo shifter 24 that imitates a shifter used for the shifting operation of a manual transmission internal combustion locomotive. The pseudo shifter 24 may be a pseudo sequential shifter that imitates a sequential shifter like a paddle shifter, or a pseudo H-type shifter that imitates an H-type shifter. Here, it is assumed that the pseudo shifter 24 is a pseudo paddle shifter that imitates a paddle shifter.

[0017] The pseudo shifter 24 has a structure similar to a shift paddle attached to the steering wheel or the steering shaft, and the left and right paddles can be moved independently. A shift position sensor 14 is provided in the pseudo shifter 24. The shift position sensor 14 outputs an upshift signal when the right paddle is pulled, and outputs a downshift signal when the left paddle is pulled.

[0018] In addition, the electric vehicle 100 is provided with a human-machine interface (HMI) 20 as an interface with the driver and a pseudo tachometer 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 through a touch operation on the touch panel display. The pseudo tachometer 21 displays the virtual engine rotation speed, which will be described later, towards the driver.

[0019] The electric vehicle 100 is provided with a control device 101. The sensors and devices to be controlled mounted on the electric vehicle 100 are connected to the control device 101 through an in-vehicle network. In addition to the vehicle speed sensor 11, the accelerator pedal stroke sensor 12, the brake pedal stroke sensor 13, and the shift position sensor 14, various other sensors are mounted on the electric vehicle 100.

[0020] The control device 101 is typically an electronic control unit (ECU). The control device 101 may be a combination of a plurality of ECUs. The control device 101 includes at least a processing circuit 102 and a memory 103. The processing circuit 102 may be, for example, a CPU, or a combination of a CPU and an FPGA. The memory 103 includes a RAM for temporarily recording data, and a ROM for storing a program 104 executable by the processing circuit 102 and various data 105 related to the program. The memory 103 may be built into the processing circuit 102. The program 104 is composed of a plurality of instruction codes. The processing circuit 102 reads the program 104 and the data 105 from the memory 103 and executes them, and generates a control signal based on the signals acquired from each sensor. The number of processing circuits 102 included in the control device 101 may be one or plural.

[0021] 3. Functions of the control device 3-1. Control modes The control device 101 can control the electric vehicle 100 in various control modes. The control mode can be selected by the driver himself / herself by touching the touch panel display of the HMI20. Specifically, by touching the touch panel display of the HMI20, one or a plurality of programs 104 associated with each touch operation are read out from the memory 103 and executed by the processing circuit 102.

[0022] The control modes selectable on the HMI20 include an automatic mode and a manual 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 a steering wheel (not shown). In the automatic mode, the shift operation of the pseudo shifter 24 is disabled. The manual mode is a control mode for operating the electric vehicle 100 like a manually shifted internal combustion engine vehicle. In the manual mode, the operation when the gear ratio of the manual transmission is switched is reproduced by the shift operation of the pseudo shifter 24.

[0023] 3-2. Vehicle Model When one or more programs 104 for torque control stored in the memory 103 are executed by the processing circuit 102, the control device 101 functions as a torque control device. A control mode signal is input to the control device 101 functioning as a torque control device from the HMI 20. The control mode signal includes information regarding the control mode selected by the driver. When the control mode is switched to the manual mode, the control device 101 calculates the drive wheel torque generated at the drive wheels using the vehicle model, and generates a motor torque command value to be given to the inverters 3F and 3R based on the drive wheel torque.

[0024] FIG. 2 is a diagram showing the configuration of a vehicle model MOD01 provided in the control device 101. The vehicle model MOD01 is composed of a driver model MOD10, an engine model MOD11, a clutch model MOD12, a manual transmission model MOD13, and an axle / drive wheel model MOD14. The internal combustion engine virtually realized by the vehicle model MOD01 is referred to as a virtual internal combustion engine, the clutch virtually realized is referred to as a virtual clutch, and the manual transmission virtually realized is referred to as a virtual manual transmission. And the manual transmission type internal combustion engine vehicle virtually realized by the set thereof is referred to as a virtual vehicle.

[0025] In the driver model MOD10, a model driver is modeled. A model driver is a skilled driver who is accustomed to driving a manually shifted internal combustion engine vehicle. The driver model MOD10 can also be said to be a model of a virtual power train control unit (PCU) that integrally controls a virtual internal combustion engine, a virtual clutch, and a virtual manual transmission. The driver model MOD10 receives, as input information, the accelerator opening of the accelerator pedal 22, the shift position of the pseudo shifter 24, the vehicle speed of the electric vehicle 100, and the virtual engine rotation speed of the virtual internal combustion engine. Then, based on these input information, the driver model MOD10 calculates the virtual accelerator opening of the virtual internal combustion engine, the virtual clutch opening of the virtual clutch, and the virtual gear stage of the virtual manual transmission. Note that the accelerator opening obtained by the accelerator pedal stroke sensor 12 represents the magnitude of the torque demand of the driver for the electric vehicle 100, while the virtual accelerator opening represents the magnitude of the torque demand of the model driver for the virtual vehicle.

[0026] In the engine model MOD11, a virtual internal combustion engine is modeled. The engine model MOD11 calculates the virtual engine rotation speed. The virtual engine rotation speed is calculated from the vehicle speed, the virtual overall reduction ratio, and the slip ratio of the virtual clutch. The vehicle speed is obtained from the signal of the vehicle speed sensor 11. The virtual overall reduction ratio is a numerical value obtained by multiplying the virtual gear ratio of the virtual manual transmission by the virtual reduction ratio determined by the mechanical structure from the virtual manual transmission to the drive wheels. Since the virtual reduction ratio is constant, if the vehicle speed is obtained, the rotation speed of the output shaft of the virtual manual transmission (virtual output shaft rotation speed) is uniquely determined. Then, by multiplying the virtual output shaft rotation speed by the virtual gear ratio, the rotation speed of the input shaft of the virtual manual transmission (virtual input shaft rotation speed) is calculated. When the virtual clutch is fully engaged, the virtual engine rotation speed coincides with the virtual input shaft rotation speed. Here, assuming the virtual input shaft rotation speed is Np and the virtual gear ratio is Rt, the virtual engine rotation speed Ne in the engaged state of the virtual clutch is represented by the following formula (1). Ne = Np × Rt ···(1)

[0027] However, when simulating the behavior of a manual transmission internal combustion engine vehicle during fuel cut-off, the engine model MOD11 calculates the virtual engine speed using a method different from the calculation method shown in Equation (1). Since fuel cut-off is an engine control executed when the engine speed becomes excessive, even in the electric vehicle 100 that simulates a manual transmission internal combustion engine vehicle, a process of simulating fuel cut-off is performed when the virtual engine speed becomes excessive. The display of the virtual engine speed calculated by a method different from the normal one on the pseudo tachometer 21 is also one of the processes of simulating fuel cut-off. Let the virtual engine torque be Te, the virtual clutch transmission torque be Tc, and the moment of inertia of the virtual internal combustion engine be J. Then, the virtual engine speed Ne during the execution of the process of simulating fuel cut-off is expressed by the following Equations (2) and (3). Details of the virtual engine torque Te and the virtual clutch transmission torque Tc used in Equation (3) will be described later. Ne = dNe + Ne i-1 ···(2) dNe = (Te - Tc) / J ···(3)

[0028] In addition, the engine model MOD11 calculates the virtual engine torque. The virtual engine torque is calculated from the virtual engine speed and the virtual accelerator opening using a map as shown in a graph in FIG. 2. The virtual accelerator opening is calculated by the driver model MOD10. In the engine model MOD11, the relationship between the virtual engine speed and the virtual engine torque is defined for each virtual accelerator opening. However, when simulating the behavior during fuel cut-off, the engine model MOD11 does not use the above map and fixes the virtual engine torque to the fuel cut-off torque described later. The virtual engine torque is input from the engine model MOD11 to the clutch model MOD12.

[0029] In the clutch model MOD12, a virtual clutch is modeled. The clutch model MOD12 calculates a virtual torque transmission gain. The virtual torque transmission gain is a gain for calculating the torque transmission degree of the virtual clutch. The virtual torque transmission gain is calculated from the virtual clutch opening using a map as shown in a graph in FIG. 2. The virtual clutch opening is calculated in the driver model MOD10. When the virtual clutch is engaged, the clutch model MOD12 calculates the virtual clutch torque using the virtual torque transmission gain. The virtual clutch torque is input from the clutch model MOD12 to the manual transmission model MOD13.

[0030] In the manual transmission model MOD13, a virtual manual transmission is modeled. The manual transmission model MOD13 calculates a virtual gear ratio. The virtual gear ratio is a gear ratio determined by the virtual gear stage in the virtual manual transmission. The virtual gear ratio is calculated from the virtual gear stage using a map as shown in a graph in FIG. 2. The virtual gear stage is calculated in the driver model MOD10 based on the shift position selected by the operation of the pseudo-shifter 24. The manual transmission model MOD13 calculates the virtual transmission torque using the virtual gear ratio and the virtual clutch torque. The virtual transmission torque is input from the manual transmission model MOD13 to the axle / drive wheel model MOD14.

[0031] As represented by the aforementioned formula (1), there is a proportional relationship between the virtual engine speed and the virtual input shaft rotational speed. And the virtual gear ratio is the proportionality constant in that proportional relationship. Since the virtual gear ratio is determined by the shift position of the pseudo-shifter 24, the switching of the shift position by the operation of the pseudo-shifter 24 changes the proportional relationship between the virtual engine speed and the virtual input shaft rotational speed. Since the virtual input shaft rotational speed is proportional to the vehicle speed, it can be said that the switching of the shift position changes the proportional relationship between the virtual engine speed and the vehicle speed.

[0032] In the axle-drive wheel model MOD14, the virtual torque transmission system from the axle to the drive wheels is modeled. The axle-drive wheel model MOD14 calculates the drive wheel torque. The drive wheel torque is calculated using the virtual transmission torque and the virtual reduction ratio from the virtual manual transmission to the drive wheels. 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. By multiplying the drive wheel torque by the torque distribution ratio 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 torque generated in the front electric motor 4F via the front inverter 3F is calculated. Also, by multiplying the drive wheel torque by the torque distribution ratio 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 torque generated in the rear electric motor 4R via the rear inverter 3R is calculated.

[0033] 3-3. Reproduction of the Behavior during Fuel Cut-off of a Manual Transmission Diesel Locomotive 3-3-1. Torque Control The control device 101 can reproduce the behavior during fuel cut-off of a manual transmission diesel locomotive in the electric vehicle 100. One of the behaviors during fuel cut-off of a manual transmission diesel locomotive that can be recognized by the driver is the change in the longitudinal acceleration generated in the vehicle. The control device 101 reproduces the change in the longitudinal acceleration during fuel cut-off by controlling the torques output by the electric motors 4F and 4R so as to simulate the change in the torque of the internal combustion engine during fuel cut-off.

[0034] Figure 3 is a flowchart showing the torque control routine that simulates the change in the torque of the internal combustion engine during fuel cut-off. The engine model MOD11 of the control device 101 is configured to execute the routine shown in Figure 3 at a predetermined cycle. Hereinafter, the torque control routine will be described with reference to Figure 3. Note that when executing the torque control routine, the control device 101 functions as a torque control device.

[0035] In step S101, it is determined whether the F / C request flag indicating that fuel cut is in progress is off. If the F / C request flag is off, that is, if fuel cut is not being executed, step S102 is executed. If the F / C request flag is on, that is, if fuel cut is being executed, step S105 is executed.

[0036] When the F / C request flag is off, in step S102, it is determined whether the virtual engine rotation speed Ne is equal to or higher than the F / C start rotation speed. The F / C start rotation speed is a threshold value (first threshold value) for determining the rotation state of the virtual internal combustion engine. When the virtual engine rotation speed Ne is equal to or higher than the F / C start rotation speed, it can be determined that the virtual internal combustion engine is in an over-rotation state. Until the virtual engine rotation speed Ne reaches the F / C start rotation speed, subsequent processing is skipped.

[0037] When the virtual engine rotation speed Ne reaches the F / C start rotation speed, steps S103 and S104 are executed. In step S103, the F / C request flag is turned on. Then, in step S104, the virtual engine torque Te is set to a predetermined F / C torque for fuel cut. The F / C torque is set to such a magnitude that the driver can feel the change in acceleration when the virtual engine torque Te, which is the basis for calculating the drive wheel torque, is switched from the user request torque calculated from the accelerator opening to the F / C torque. That is, by executing step S104, the change in the longitudinal acceleration during fuel cut is reproduced.

[0038] When the F / C request flag is on, in step S105, it is determined whether the virtual engine rotational speed Ne is lower than the F / C return rotational speed. The F / C return rotational speed is a threshold value (second threshold value) for determining the rotational state of the virtual internal combustion engine, and is set to a value lower than the F / C start rotational speed which is the first threshold value. When the virtual engine rotational speed Ne is lower than the F / C return rotational speed, it can be determined that the virtual internal combustion engine has escaped from the over-rotation state. Until the virtual engine rotational speed Ne decreases to the F / C return rotational speed, the subsequent processing is skipped.

[0039] When the virtual engine rotational speed Ne has decreased to the F / C return rotational speed, steps S106 and S107 are executed. In step S106, the F / C request flag is turned off. Then, in step S107, the virtual engine torque Te is returned from the F / C torque to the user request torque. The user request torque is calculated based on the virtual engine rotational speed and the virtual accelerator opening degree using a map as shown by the graph in FIG. 2.

[0040] 3-3-2. Display Control Another behavior during fuel cut of a manual transmission internal combustion engine vehicle that can be recognized by the driver is the change in the engine rotational speed displayed on the tachometer. The control device 101 reproduces the change in the engine rotational speed displayed on the tachometer during fuel cut by controlling the display of the pseudo tachometer 21 so as to simulate the change in the display of the tachometer during fuel cut.

[0041] FIG. 4 is a flowchart showing a routine for display control that simulates the change in the engine rotational speed. The engine model MOD11 of the control device 101 is configured to execute the routine shown in FIG. 4 at a predetermined cycle. Hereinafter, the routine for controlling the display of the pseudo tachometer 21 will be described with reference to FIG. 4. When executing the display control routine, the control device 101 functions as a display control device.

[0042] In step S201, it is determined whether the Ne calculation change flag indicating that the calculation method of the virtual engine rotational speed Ne is being changed is off. When the Ne calculation change flag is off, that is, when the virtual engine rotational speed is calculated by the normal calculation method represented by Equation (1), step S202 is executed. When the Ne calculation change flag is on, that is, when the virtual engine rotational speed is calculated by the calculation methods represented by Equation (2) and Equation (3), step S206 is executed.

[0043] When the Ne calculation change flag is off, in step S202, it is determined whether the virtual input shaft rotational speed Nin is equal to or higher than the F / C start rotational speed. Until the virtual input shaft rotational speed Nin reaches the F / C start rotational speed, subsequent processing is skipped.

[0044] When the virtual input shaft rotational speed Nin reaches the F / C start rotational speed, steps S203 to S205 are executed. In step S203, the Ne calculation change flag is turned on. Then, in step S204, the calculation method of the virtual engine rotational speed Ne is switched from the normal calculation method represented by Equation (1) to the calculation methods represented by Equation (2) and Equation (3). The virtual engine torque Te in Equation (3) is the torque calculated by the torque control routine shown in FIG. 3, and the virtual clutch transmission torque Tc in Equation (3) is the running resistance torque acting on the output side disk of the virtual clutch. The aforementioned F / C torque is set to a value smaller than the virtual clutch transmission torque Tc. Therefore, at least while the F / C request flag is on, the virtual engine rotational speed Ne displayed on the pseudo tachometer 21 gradually decreases. That is, by executing step S204, the change in the engine rotational speed displayed on the tachometer during fuel cut is reproduced. In step 205, a lower limit guard process is performed to prevent the virtual engine rotational speed Ne from decreasing excessively.

[0045] When the Ne calculation change flag is ON, at step S206, it is determined whether the virtual input shaft rotation speed Nin is lower than the F / C return rotation speed. Until the virtual input shaft rotation speed Nin drops to the F / C return rotation speed, step S209 is executed. At step S209, it is determined whether the accelerator opening is OFF, that is, whether the accelerator pedal 22 is released. If the accelerator opening is ON, that is, if the accelerator pedal 22 is depressed, the subsequent processing is skipped.

[0046] When the virtual input shaft rotation speed Nin drops to the F / C return rotation speed, or when the accelerator pedal 22 is released, steps S207 and S208 are executed. At step S207, the Ne calculation change flag is turned OFF. Then, at step S208, the calculation method of the virtual engine rotation speed Ne is switched from the calculation methods represented by equations (2) and (3) to the normal calculation method represented by equation (1).

[0047] 4. Specific Examples of Control Results by the Control Device A specific example of the behavior during fuel cut of a manual transmission internal combustion locomotive reproduced in the electric vehicle 100 by the control device 101 will be described with reference to FIG. 5. In the time chart shown in FIG. 5, the changes over time of the virtual input shaft rotation speed Nin, the virtual engine rotation speed Ne, the F / C request flag, the Ne calculation change flag, the virtual engine torque for calculating the virtual engine rotation speed (Te for Ne calculation), and the virtual engine torque for calculating the drive wheel torque (Te for Tp calculation) are depicted.

[0048] According to the time chart shown in FIG. 5, before time t1, the virtual engine rotational speed Ne is calculated by Equation (1), and the virtual engine rotational speed Ne is consistent with the virtual input shaft rotational speed Nin. When the accelerator pedal 22 is depressed and the virtual engine rotational speed Ne and the virtual input shaft rotational speed Nin increase, at time t1, the virtual engine rotational speed Ne and the virtual input shaft rotational speed Nin reach the F / C start rotational speed which is the first threshold value. In response to the virtual engine rotational speed Ne reaching the F / C start rotational speed, the F / C request flag is turned on, and in response to the virtual input shaft rotational speed Nin reaching the F / C start rotational speed, the Ne calculation change flag is turned on.

[0049] In response to the F / C request flag being turned on, the virtual engine torque Te is stepwise decreased from the user request torque to the F / C torque. However, the F / C torque is different between the Te for Ne calculation which is the virtual engine torque for calculating the virtual engine rotational speed and the Te for Tp calculation which is the virtual engine torque for calculating the drive wheel torque. In the Te for Ne calculation, the F / C torque is decreased to a friction torque lower than the running resistance torque (Te equivalent to R / L). On the other hand, in the Te for Tp calculation, the F / C torque is decreased to a predetermined lower limit torque (lower limit Te) greater than zero. However, also in the Te for Tp calculation, the F / C torque can be made zero or less, or can be decreased to the friction torque.

[0050] In response to the Ne calculation change flag being turned on, the calculation of the virtual engine rotational speed Ne is switched from the calculation by Equation (1) to the calculations by Equations (2) and (3). The calculation of the virtual engine rotational speed Ne by Equations (2) and (3) continues until time t2 when the virtual input shaft rotational speed Nin decreases to the F / C return rotational speed which is the second threshold value.

[0051] Between time t1 and time t2, the virtual engine rotational speed Ne decreases to the F / C return rotational speed. In response to the virtual engine rotational speed Ne decreasing to the F / C return rotational speed, the F / C request flag is turned off. On the other hand, since the virtual input shaft rotational speed Nin is equal to or higher than the F / C return rotational speed, the Ne calculation change flag remains on. In response to the F / C request flag being turned off, the virtual engine torque Te is switched from the F / C torque to the user request torque. In the example shown in FIG. 5, between time t2, the virtual engine rotational speed Ne reciprocates multiple times between the F / C return rotational speed and the F / C start rotational speed, and each time the virtual engine torque Te changes stepwise between the F / C torque and the user request torque.

[0052] In response to the virtual input shaft rotational speed Nin decreasing to the F / C return rotational speed at time t2, the calculation of the virtual engine rotational speed Ne is switched back to the calculation according to Equation (1). As a result, the virtual engine rotational speed Ne coincides with the virtual input shaft rotational speed Nin.

[0053] At time t3, the virtual engine rotational speed Ne and the virtual input shaft rotational speed Nin reach the F / C start rotational speed again. In response to the virtual engine rotational speed Ne reaching the F / C start rotational speed, the F / C request flag is turned on, and the virtual engine torque Te is decreased stepwise from the user request torque to the F / C torque. Also, in response to the virtual input shaft rotational speed Nin reaching the F / C start rotational speed, the Ne calculation change flag is turned on, and the calculation of the virtual engine rotational speed Ne is switched back to the calculation according to Equations (2) and (3).

[0054] At time t4, the accelerator pedal 22 is released. In response to this, the Ne calculation change flag is turned off, and the calculation of the virtual engine rotational speed Ne is switched back to the calculation according to Equation (1).

[0055] As described above, when the virtual engine rotational speed indicated by the pseudo tachometer 21 reaches the F / C start rotational speed (first threshold) with the accelerator pedal 22 depressed, the virtual engine rotational speed indicated by the pseudo tachometer 21 gradually decreases regardless of the vehicle speed. This corresponds to the decrease in the engine rotational speed indicated by the tachometer when fuel cut is performed in a manual transmission internal combustion engine vehicle. That is, in the electric vehicle 100, the behavior during fuel cut in a manual transmission internal combustion engine vehicle is reproduced.

Explanation of Signs

[0056] 2 Battery, 4F Front electric motor, 4R Rear electric motor, 11 Vehicle speed sensor, 12 Accelerator pedal stroke sensor, 14 Shift position sensor, 15 Paddle shift switch, 16 Clutch pedal stroke sensor, 20 HMI, 21 Pseudo tachometer, 22 Accelerator pedal, 24 Pseudo shifter, 100 Electric vehicle, 101 Control device, 102 Processing circuit, 103 Memory

Claims

1. An electric vehicle having an electric motor as a drive source, an accelerator pedal, a pseudo-shifter modeled after a shifter used for shift operations of a manual transmission internal combustion engine vehicle, a pseudo-tachometer modeled after a tachometer of the manual transmission internal combustion engine vehicle, and a display control device for changing a numerical value indicated by the pseudo-tachometer, wherein the display control device makes the numerical value proportional to the vehicle speed of the electric vehicle and changes the proportional relationship between the numerical value and the vehicle speed according to a shift position selected by an operation of the pseudo-shifter, and when the numerical value reaches a first threshold value while the accelerator pedal is depressed, gradually decreases the numerical value without following the proportional relationship characterizing the electric vehicle.

2. In the electric vehicle according to Claim 1, wherein the display control device changes the numerical value again according to the proportional relationship when the numerical value decreases to a second threshold value lower than the first threshold value while the accelerator pedal is depressed characterizing the electric vehicle.

3. In the electric vehicle according to Claim 2, wherein the display control device changes the numerical value again according to the proportional relationship when the accelerator pedal is released before the numerical value decreases to the second threshold value characterizing the electric vehicle.

4. In the electric vehicle according to any one of Claims 1 to 3, further comprising a torque control device for controlling the torque of the electric motor, wherein the torque control device changes the torque according to the opening degree of the accelerator pedal, and when the numerical value reaches the first threshold value, decreases the torque regardless of the opening degree of the accelerator pedal characterizing the electric vehicle.

5. In the electric vehicle according to Claim 4, wherein the torque control device changes the torque again according to the opening degree of the accelerator pedal when the numerical value decreases to a second threshold value lower than the first threshold value characterizing the electric vehicle.

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