Electric vehicle

Abstract

To provide an electric vehicle capable of simulating a gear change operation of a manual shift type internal combustion engine which can complete, when performing the gear change operation while a driver steps down an accelerator pedal, the gear change operation without giving a sense of incongruity to the driver.SOLUTION: A controller comprises the steps of: changing a virtual accelerator opening degree from a demand opening degree to a full closing degree on receiving changing of a shift position through operation of a pseudo shifter; changing a virtual clutch opening degree from an engagement opening degree to a disengagement opening degree on receiving completion of changing the virtual accelerator opening degree into the full closing degree; changing a virtual gear stage into a demand gear stage on receiving completion of changing the virtual clutch opening degree into the disengagement opening degree; changing the virtual clutch opening degree into the engagement opening degree again on receiving convergence of rotational speed difference between a virtual engine rotational speed and a virtual input shaft rotational speed after changing the virtual gear stage into the demand gear stage; and changing the virtual accelerator opening degree from the full closing degree to the demand opening degree on receiving completion of changing the virtual clutch opening degree into the disengagement opening degree.SELECTED DRAWING: Figure 5

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 shifting operation of a vehicle equipped with a manual transmission having an internal combustion engine as a power source (hereinafter referred to as a manual transmission type internal combustion engine vehicle) by controlling an electric motor. The electric vehicle disclosed in this publication includes a vehicle model simulating a manual transmission type internal combustion engine vehicle and a driver model simulating an exemplary driver. The vehicle model includes an engine model, a clutch model, and a manual transmission model. The driver model calculates the clutch pedal depression amount of a virtual clutch simulated by the clutch model based on the rotational speed difference between the rotational speed of the input shaft of a virtual manual transmission simulated by the manual transmission model and the rotational speed of a virtual engine simulated by the engine model.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the electric vehicle disclosed in the above publication, the driver can perform a shifting operation while depressing the accelerator pedal. However, since the virtual clutch is released in response to the shifting operation, the rotational speed of the virtual engine will increase rapidly. If a pseudo-tachometer that displays the rotational speed of the virtual engine is provided, for example, on the instrument panel of the vehicle, the driver will feel discomfort with the rapid increase in the rotational speed of the virtual engine displayed on the pseudo-tachometer.

[0005] In the electric vehicle disclosed in the above publication, the virtual clutch is not engaged unless the rotational speed difference calculated by the driver model is reduced. Therefore, when a gear shift operation is performed while the driver is depressing the accelerator pedal, the gear shift operation is not completed due to an increase in the rotational speed difference caused by an increase in the virtual engine rotational speed. During that time, since the behavior of a manual transmission internal combustion engine vehicle with the clutch disengaged is simulated in the electric vehicle, the driver will feel more discomfort the longer it takes to complete the gear shift operation.

[0006] The present disclosure has been made in view of the above problems. One object of the present disclosure is to complete gear shifting without causing discomfort to the driver even when a gear shift operation is performed while the driver is depressing the accelerator pedal in an electric vehicle capable of simulating the gear shift operation of a manual transmission internal combustion engine vehicle.

Means for Solving the Problems

[0007] An electric vehicle according to one 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 a gear shift operation of a manual transmission internal combustion engine vehicle, and a control device that changes the relationship between the vehicle speed of the electric vehicle, the accelerator opening of the accelerator pedal, and the torque of the electric motor in response to an operation of the pseudo shifter. The control device includes a memory that stores a vehicle model in which a virtual vehicle is modeled, and a processing circuit coupled to the memory that executes the vehicle model.

[0008] The vehicle model includes an engine model in which a virtual internal combustion engine is modeled, a clutch model in which a virtual clutch is modeled, a transmission model in which a virtual manual transmission is modeled, and a driver model in which a model driver is modeled. The driver model is a model that 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 based on the accelerator opening of the accelerator pedal, the shift position of the pseudo shifter, the vehicle speed of the electric vehicle, and the virtual engine rotational speed of the virtual internal combustion engine.

[0009] Upon receiving a change in the shift position due to an operation of a pseudo shifter, the driver model changes the virtual accelerator opening from the required opening to the fully closed opening. The required opening means the accelerator opening required by the driver through the operation of the accelerator pedal. Upon completion of the change of the virtual accelerator opening to the fully closed opening, the driver model changes the virtual clutch opening from the engaged opening to the released opening. Upon completion of the change of the virtual clutch opening to the released opening, the driver model changes the virtual gear stage to the required gear stage corresponding to the shifted position after the change. After the change of the virtual gear stage to the required gear stage, upon convergence within a predetermined range of the rotational speed difference between the virtual engine rotational speed and the virtual input shaft rotational speed of the virtual manual transmission, the driver model changes the virtual clutch opening from the released opening to the engaged opening. Then, upon completion of the change of the virtual clutch opening to the released opening, the driver model changes the virtual accelerator opening from the fully closed opening to the required opening.

[0010] When the operation of the pseudo shifter is a downshift operation, upon completion of the change of the virtual gear stage to the required gear stage, the driver model may temporarily increase the virtual accelerator opening from the fully closed opening. Then, upon convergence within a predetermined range of the rotational speed difference between the virtual engine rotational speed and the virtual input shaft rotational speed of the virtual manual transmission, the driver model may change the virtual clutch opening from the released opening to the engaged opening.

Advantages of the Invention

[0011] According to the electric vehicle according to one embodiment of the present disclosure, upon receiving a change in the shift position due to an operation of a pseudo shifter, the virtual accelerator opening of the virtual internal combustion engine is changed from the required opening to the fully closed opening. For this reason, the virtual engine rotational speed does not increase in response to the operation of the driver's accelerator pedal, and the rotational speed difference between the virtual engine rotational speed and the virtual input shaft rotational speed of the virtual manual transmission quickly converges within a predetermined range. Thereby, even when the driver performs a shifting operation while depressing the accelerator pedal, the shifting can be completed without giving the driver a sense of discomfort.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0013] 1. Configuration of the power system of an 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, the configuration of the power system of the electric vehicle 100 will be described with reference to FIG. 1.

[0014] The electric vehicle 100 is provided with two electric motors (M) 4F and 4R at the front and rear as driving power sources for traveling. 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.

[0015] An inverter (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 the battery (BATT) 2. That is, the electric vehicle 100 is a battery electric vehicle (BEV) that runs on 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.

[0016] 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.

[0017] 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. Further, 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.

[0018] The accelerator pedal 22 and the brake pedal 23 are driving operation members used for driving the electric vehicle 100. Separately from these driving operation members, the electric vehicle 100 is provided with a pseudo shifter 24 that imitates a shifter used for the gear shifting operation of a manual transmission internal combustion engine vehicle. 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.

[0019] 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.

[0020] In addition, the electric vehicle 100 includes 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 an input from the driver by a touch operation on the touch panel display. The pseudo tachometer 21 displays the virtual engine rotational speed, which will be described later, toward the driver.

[0021] The electric vehicle 100 includes a control device 101. Sensors and devices to be controlled mounted on the electric vehicle 100 are connected to the control device 101 by 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.

[0022] 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 may be 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 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 more.

[0023] 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 HMI 20. Specifically, 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 processing circuit 102.

[0024] The control modes selectable on the HMI 20 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 invalidated. The manual mode is a control mode for operating the electric vehicle 100 like a manually shifted internal combustion locomotive. 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.

[0025] 3-2. Vehicle Model When one or more torque control programs 104 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 applied to the inverters 3F and 3R based on the drive wheel torque.

[0026] 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.

[0027] In the engine model MOD11, a virtual internal combustion engine is modeled. In the clutch model MOD12, a virtual clutch is modeled. In the manual transmission model MOD13, a virtual manual transmission is modeled. In the axle / drive wheel model MOD14, a virtual torque transmission system from the axle to the drive wheels is modeled. And in the driver model MOD10, a model driver is modeled. The model driver is a skilled driver familiar with the operation of a manual transmission type internal combustion engine vehicle. The driver model MOD10 can also be said to be a model in which a virtual power train control unit (PCU) that integrally controls the virtual internal combustion engine, the virtual clutch, and the virtual manual transmission is modeled. Input and output of calculation results are performed between the respective models.

[0028] The engine model MOD11 calculates the virtual engine rotational speed. The virtual engine rotational speed is calculated by different calculation methods depending on the engaged state and disengaged state of the virtual clutch. In the engaged state of the virtual clutch, the virtual engine rotational 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 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. In the disengaged state of the virtual clutch, the virtual engine rotational speed is calculated using the virtual accelerator opening and the virtual moment of inertia of the virtual internal combustion engine. For example, the virtual engine torque may be calculated from the current virtual engine rotational speed and the virtual accelerator opening, and the change amount of the virtual engine rotational speed after a unit time may be calculated based on the virtual engine torque and the virtual moment of inertia.

[0029] Also, the engine model MOD11 calculates the virtual engine torque. The virtual engine torque is calculated from the virtual engine rotational speed and the virtual accelerator opening using a map as shown by the 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 rotational speed and the virtual engine torque is defined for each virtual accelerator opening. The virtual engine torque is input from the engine model MOD11 to the clutch model MOD12.

[0030] The clutch model MOD12 calculates the 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 by the graph in FIG. 2. The virtual clutch opening is calculated by 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.

[0031] The manual transmission model MOD13 calculates a virtual gear ratio. The virtual gear ratio is the 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 by the graph in Figure 2. The virtual gear stage is calculated by the driver model MOD10. 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 and drive wheel model MOD14.

[0032] The axle and 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 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 is calculated.

[0033] 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. For calculating these virtual operation amounts, the driver model MOD10 executes the state determination process P10, the virtual accelerator opening calculation process P21, the virtual clutch opening calculation process P22, and the virtual gear stage calculation process P23.

[0034] In the state determination process P10, the vehicle state and the shift state of the virtual vehicle are determined. The details of the content of the state determination process P10 will be described in detail later. The shift state determined in the state determination process P10 is used in the virtual accelerator opening calculation process P21, the virtual clutch opening calculation process P22, and the virtual gear stage calculation process P23.

[0035] In the virtual accelerator opening calculation process P21, the virtual accelerator opening is calculated based on the accelerator opening obtained by the accelerator pedal stroke sensor 12 and the shift state of the virtual vehicle determined in the state determination process P10. The accelerator opening obtained by the accelerator pedal stroke sensor 12 represents the magnitude of the torque demand for the electric motors 4F and 4R. On the other hand, the virtual accelerator opening represents the magnitude of the torque demand for the virtual internal combustion engine of the virtual vehicle. The virtual accelerator opening calculation process P21 can also be said to be a process of correcting the accelerator opening obtained by the accelerator pedal stroke sensor 12 for the virtual internal combustion engine. The virtual accelerator opening calculated in the virtual accelerator opening calculation process P21 is input to the engine model MOD11.

[0036] In the virtual clutch opening calculation process P22, the virtual clutch opening is calculated based on the shift state of the virtual vehicle determined in the state determination process P10. The virtual clutch opening is basically set to 0%. That is, the basic state of the virtual clutch is the engaged state. When an upshift signal or a downshift signal is input from the shift position sensor 14, the virtual clutch opening is temporarily set to 100%. This means that when the shift operation of the pseudo-shifter 24 is performed, the virtual clutch is temporarily disengaged. The virtual clutch opening calculated in the virtual clutch opening calculation process P22 is input to the clutch model MOD12.

[0037] In the virtual gear stage calculation process P23, the virtual gear stage is calculated based on the shift position obtained by the shift position sensor 14 and the shift state of the virtual vehicle determined in the state determination process P10. The number of stages of the virtual gear stage is the number of positions of the pseudo-shifter 24 plus the neutral position. The virtual gear stage calculated in the virtual gear stage calculation process P23 is input to the manual transmission model MOD13.

[0038] Figure 3 is a diagram for explaining the state determination process P10. The state determination process P10 includes a vehicle state determination process P11 and a shift state determination process P12. Among these two processes P11 and P12, the main process is the vehicle state determination process P11. When a predetermined condition is satisfied in the vehicle state determination process P11, the shift state determination process P12 is executed.

[0039] In the vehicle state determination process P11, steps S11, S12, and S13 are executed. In step S11, it is determined whether there is a shift request from the driver. When an upshift signal is input from the shift position sensor 14 or a downshift signal is input, it is determined that the driver is requesting a shift. When a shift request from the driver is received, the shift is started, and a shifting flag indicating that the virtual vehicle is in the middle of a shift is switched from off to on.

[0040] If it is determined that there is a shift request from the driver, in step S12, the virtual vehicle is determined to be in a shift state. If it is determined that there is no shift request from the driver, in step S13, the virtual vehicle is determined to be in a state other than the shift state. The state other than the shift state includes, for example, a state where the pseudo shifter 24 is not operated. When it is determined that the virtual vehicle is in a shift state, the shift state determination process P12 is executed.

[0041] In the shift state determination process P12, it is determined which shift state the virtual vehicle is in. The shift states include six states from shift state M1 to shift state M6. Also, the transition conditions between those shift states include seven conditions from transition condition E1 to transition condition E7. M1 - M6 are called shift state IDs, and E1 - E7 are called transition condition IDs.

[0042] In the shift state M1, the virtual accelerator opening is reduced from the driver's required accelerator opening to zero. The accelerator opening required by the driver is the accelerator opening obtained by the accelerator pedal stroke sensor 12. The transition condition E1 from the shift state M1 to the shift state M2 is that the virtual accelerator opening becomes zero. In the shift state M2, the virtual clutch is released. That is, the virtual clutch opening is increased to 100%. The transition condition E2 from the shift state M2 to the shift state M3 is that the release of the virtual clutch is completed. In the shift state M3, the virtual gear stage is changed to the virtual gear stage corresponding to the shift position after the shift operation. The change of the virtual gear stage passes through neutral.

[0043] When the change of the virtual gear stage is an upshift, a direct transition is made from the shift state M3 to the shift state M5. The transition condition E4 from the shift state M3 to the shift state M5 is that the rotational speed difference between the virtual engine rotational speed and the virtual input shaft rotational speed falls within a predetermined range. On the other hand, when the change of the virtual gear stage is a downshift, a transition is made from the shift state M3 to the shift state M5 via the shift state M4. The transition condition E3 from the shift state M3 to the shift state M4 is that the gear shift to the changed virtual gear stage is completed. In the shift state M4, the virtual engine rotational speed and the virtual input shaft rotational speed of the virtual manual transmission are synchronized. The transition condition E5 from the shift state M4 to the shift state M5 is that the rotational speed difference between the virtual engine rotational speed and the virtual input shaft rotational speed falls within a predetermined range. However, by changing the setting of the manual mode by operating the HMI20, even when the change of the virtual gear stage is a downshift, a direct transition can also be made from the shift state M3 to the shift state M5.

[0044] In the shift state M5, the virtual clutch is engaged. That is, the virtual clutch opening is reduced to 0%. The transition condition E6 from the shift state M5 to the shift state M6 is that the engagement of the virtual clutch is completed. In the shift state M6, the virtual accelerator opening returns to the accelerator opening required by the driver, that is, the accelerator opening obtained by the accelerator pedal stroke sensor 12. The transition condition E7 from the shift state M6 to the shift state M1 is that the virtual accelerator opening opens to the accelerator opening required by the driver.

[0045] Figure 4 is a diagram for explaining in detail the shift state determination process P12 for each shift state ID. Each shift state from shift state M1 to shift state M6 can be represented by a virtual accelerator opening, a virtual clutch opening, and a virtual gear position.

[0046] In shift state M1, the virtual accelerator opening is changed from the opening required by the driver, who is the user (user required opening), to 0%, which is the fully closed opening, at a predetermined change rate. The virtual clutch opening is set to the engaged opening. The virtual gear position is maintained at the current gear position.

[0047] In shift state M2, the virtual accelerator opening is set to 0%. The virtual clutch opening is changed from the engaged opening to the released opening at a predetermined change rate. The virtual gear position is maintained at the current gear position.

[0048] In shift state M3, the virtual accelerator opening is set to 0%. The virtual clutch opening is set to the released opening. The virtual gear position is changed from the current gear position to neutral once and then changed to the gear position required by the driver.

[0049] In shift state M4, blipping is performed to temporarily increase the virtual accelerator opening to increase the virtual engine rotation speed. The virtual clutch opening is set to the released opening. The virtual gear position is set to the required gear position.

[0050] In shift state M5, the virtual accelerator opening is set to 0%. The virtual clutch opening is changed from the released opening to the engaged opening at a predetermined change rate. The virtual gear position is set to the required gear position.

[0051] In shift state M6, the virtual accelerator opening is changed from 0% to the user required opening at a predetermined change rate. The virtual clutch opening is set to the engaged opening. The virtual gear position is set to the required gear position. And when the virtual accelerator opening returns to the accelerator opening required by the driver, a flag indicating that the virtual vehicle is in the middle of a shift is switched from on to off.

[0052] The virtual accelerator opening calculation process P21 is executed according to the state of the virtual accelerator opening defined in each shift state M1 - M6 as described above. Also, the virtual clutch opening calculation process P22 is executed according to the state of the virtual clutch opening defined in each shift state M1 - M6. And the virtual gear stage calculation process P23 is executed according to the state of the virtual gear stage defined in each shift state M1 - M6.

[0053] 4. Specific Example of Shift Control 4 - 1. Shift Control at Upshift A specific example of the shift control at upshift executed by the control device 101 will be described with reference to FIG. 5. In the time chart shown in FIG. 5, together with the shift state ID and the transition condition ID, the upshift signal, the virtual accelerator opening, the virtual clutch opening, the virtual gear stage, the virtual engine speed, the drive wheel torque required for the electric motors 4F and 4R, and the change over time of the longitudinal acceleration generated in the electric vehicle 100 are depicted.

[0054] According to the time chart shown in FIG. 5, at time t11, an upshift signal is input from the shift position sensor 14 to the control device 101. In response to the input of the upshift signal, the virtual accelerator opening is changed from the user - required opening to 0% at a predetermined change rate. During this period, the virtual clutch opening is maintained at the engaged opening, and the virtual gear stage is maintained at the current N - stage. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, the increase in the virtual rotational speed is suppressed, and the required drive wheel torque decreases to zero.

[0055] At time t12, the change of the virtual accelerator opening to 0% is completed. In response to this, the virtual clutch opening is changed from the engaged opening to the disengaged opening at a predetermined change rate. During this period, the virtual accelerator opening is maintained at 0%, and the virtual gear stage is maintained at the current N - stage. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, the virtual rotational speed decreases, and the required drive wheel torque is maintained at zero. And as the drive wheel torque decreases to zero, the acceleration (the forward acceleration of the vehicle) generated in the vehicle decreases.

[0056] At time t13, the change of the virtual clutch opening to the release opening is completed. In response to this, the virtual gear stage is switched from the current Nth stage to neutral. Then, at time t14 when the set time has elapsed since the switch to neutral, the virtual gear stage is switched to the driver's requested gear stage (N+1 stage in the example shown in FIG. 5). During that time, the virtual accelerator opening is maintained at 0%, and the virtual clutch opening is maintained at the release opening. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, the virtual rotational speed continues to decrease, and the required drive wheel torque is maintained at zero. Then, the acceleration decreases to zero.

[0057] At time t15, the rotational speed difference between the virtual rotational speed and the virtual input shaft rotational speed (N+1 stage rotational speed in the example shown in FIG. 5) converges to the allowable speed difference. In response to this, the virtual clutch opening is changed from the release opening to the engagement opening at a predetermined change rate. During that time, the virtual accelerator opening is maintained at 0%, and the virtual gear stage is fixed to the requested gear stage. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, the virtual rotational speed further decreases, and the required drive wheel torque is maintained at zero. Then, since the drive wheel torque continues to be maintained at zero, the acceleration is also maintained at zero.

[0058] At time t16, the change of the virtual clutch opening to the engagement opening is completed. In response to this, the virtual accelerator opening is changed from 0% to the user-requested opening at a predetermined change rate. During that time, the virtual clutch opening is fixed in the engaged state, and the virtual gear stage is fixed to the requested gear stage. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, when the change of the virtual clutch opening to the engagement opening is completed, the virtual rotational speed slightly decreases stepwise and then continuously increases. Also, the required drive wheel torque temporarily increases and decreases and then continuously increases. Since the change in the required drive wheel torque is not immediately reflected in the acceleration, the acceleration remains zero during this period.

[0059] At time t17, the change of the virtual accelerator opening to the required opening is completed. As a result, the upshift requested by the driver for the electric vehicle 100 by operating the pseudo-shifter 24 is completed. After the completion of the upshift, the virtual accelerator opening is set to the required opening, the virtual clutch opening is fixed in the engaged state, and the virtual gear stage is fixed to the required gear stage. Around this time, a longitudinal shift shock occurs in the electric vehicle 100, but its magnitude is kept low. Thereafter, the acceleration changes to a magnitude corresponding to the virtual accelerator opening and the virtual gear stage.

[0060] According to the above shift control, in response to the upshift operation of the pseudo-shifter 24 by the driver, the virtual accelerator opening of the virtual internal combustion engine is changed from the required opening to 0%, which is the fully closed opening. For this reason, the virtual engine speed does not increase according to the operation of the driver's accelerator pedal 22, and the rotational speed difference between the virtual engine speed and the virtual input shaft speed of the virtual manual transmission quickly converges within a predetermined range. Thereby, even when the driver performs an upshift operation with the accelerator pedal 22 depressed, the virtual engine speed does not suddenly increase and the shift time does not become long, and the shift can be completed without giving the driver a sense of discomfort.

[0061] 4-2. Shift control during downshift 4-2-1. With blipping A specific example of the shift control during downshift executed by the control device 101 will be described with reference to FIG. 6. In the time chart shown in FIG. 6, together with the shift state ID and the transition condition ID, the upshift signal, the virtual accelerator opening, the virtual clutch opening, the virtual gear stage, the virtual engine torque, the virtual engine speed, the drive wheel torque required for the electric motors 4F and 4R, and the longitudinal acceleration generated in the electric vehicle 100 are depicted as changes over time. In this specific example, blipping is used to match the rotational speeds when engaging the virtual clutch.

[0062] According to the time chart shown in FIG. 6, a downshift signal is input from the shift position sensor 14 to the control device 101 at time t21. In response to the input of the downshift signal, the virtual accelerator opening is changed from the user-requested opening to 0% at a predetermined change rate. In the example shown in FIG. 6, since the user-requested opening is already 0%, the virtual accelerator opening is maintained at 0%. During this period, the virtual clutch opening is maintained at the engaged opening, and the virtual gear stage is maintained at the current N stage. By calculating the virtual accelerator opening, virtual clutch opening, and virtual gear stage in this way, the virtual engine torque is maintained at a constant negative value, the virtual rotational speed decreases, and the required drive wheel torque increases greatly on the negative side.

[0063] At time t22, it is determined that the virtual accelerator opening is 0%. In response to this, the virtual clutch opening is changed from the engaged opening to the disengaged opening at a predetermined change rate. During this period, the virtual accelerator opening is maintained at 0%, and the virtual gear stage is maintained at the current N stage. By calculating the virtual accelerator opening, virtual clutch opening, and virtual gear stage in this way, the virtual engine torque is maintained at a constant negative value, the virtual rotational speed decreases, and the required drive wheel torque changes to the positive side and increases to zero. Then, the deceleration (the backward acceleration of the vehicle) generated in the vehicle changes from an increase to a decrease.

[0064] At time t23, the change of the virtual clutch opening to the disengaged opening is completed. In response to this, the virtual gear stage is switched from the current N stage to neutral. During this period, the virtual accelerator opening is maintained at 0%, and the virtual clutch opening is maintained at the disengaged opening. By calculating the virtual accelerator opening, virtual clutch opening, and virtual gear stage in this way, the virtual engine torque is maintained at a constant negative value, the decreasing speed of the virtual rotational speed increases, and the required drive wheel torque is maintained at zero. Then, the deceleration decreases to zero.

[0065] At time t24, the set time elapses since the virtual gear stage was switched to neutral. In response to this, the virtual gear stage is switched to the driver's requested gear stage (N-1 stage in the example shown in FIG. 6), and the virtual accelerator opening is switched from 0% to a predetermined blipping opening. During that time, the virtual clutch opening is maintained at the released opening. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, the virtual engine torque is increased, the virtual rotational speed changes from decreasing to increasing, but the required drive wheel torque is maintained at zero. Also, since the drive wheel torque continues to be maintained at zero, the longitudinal acceleration is also maintained at zero.

[0066] At time t25, the rotational speed difference between the virtual rotational speed and the virtual input shaft rotational speed (N-1 stage rotational speed in the example shown in FIG. 6) converges to the allowable speed difference. In response to this, the virtual accelerator opening is switched from the blipping opening to 0% again, and the virtual clutch opening is changed from the released opening to the engaged opening at a predetermined change rate. During that time, the virtual gear stage is fixed to the requested gear stage. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, the virtual engine torque is maintained at a constant negative value again, the virtual rotational speed changes from increasing to decreasing, and the required drive wheel torque increases from zero to the negative side. And as the drive wheel torque increases on the negative side, the deceleration increases.

[0067] At time t26, the change of the virtual clutch opening to the engaged opening is completed. In response to this, the virtual accelerator opening is changed from 0% to the user-requested opening at a predetermined change rate. During that time, the virtual clutch opening is fixed in the engaged state, and the virtual gear stage is fixed to the requested gear stage. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, the virtual engine torque increases to the torque corresponding to the user-requested opening, and the virtual rotational speed changes to the rotational speed determined by the requested gear stage and the vehicle speed. Also, the required drive wheel torque changes from changing to the negative side to changing to the positive side. And after the direction of change of the required drive wheel torque changes, a longitudinal shift shock occurs in the electric vehicle 100, but its magnitude is kept low.

[0068] At time t27, the change of the virtual accelerator opening degree to the required opening degree is completed. As a result, the downshift requested by the driver for the electric vehicle 100 by operating the pseudo shifter 24 is completed. After the completion of the downshift, the virtual accelerator opening degree is set to the required opening degree, the virtual clutch opening degree is fixed in the engaged state, and the virtual gear stage is fixed to the required gear stage.

[0069] According to the above shift control, in response to the downshift operation of the pseudo shifter 24 by the driver, the virtual accelerator opening degree is forcibly set to 0%, which is the fully closed opening degree, and blipping is performed in accordance with the switching of the virtual gear stage to the required gear stage. Therefore, the virtual engine rotational speed does not increase in response to the operation of the driver's accelerator pedal 22, and the rotational speed difference between the virtual engine rotational speed and the rotational speed of the virtual input shaft of the virtual manual transmission converges quickly within a predetermined range due to the action of blipping. As a result, even when the driver performs a downshift operation with the accelerator pedal 22 depressed, the virtual engine rotational speed does not increase suddenly and the shift time does not become long, and the shift can be completed without giving the driver a sense of discomfort.

[0070] 4-2-2. Without blipping Another specific example of the shift control during downshift executed by the control device 101 will be described with reference to FIG. 7. In the time chart shown in FIG. 7, together with the shift state ID and the transition condition ID, the upshift signal, the virtual accelerator opening degree, the virtual clutch opening degree, the virtual gear stage, the virtual engine torque, the virtual engine speed, the drive wheel torque required for the electric motors 4F and 4R, and the change over time of the longitudinal acceleration generated in the electric vehicle 100 are depicted. In this specific example, blipping is not used for speed matching when engaging the virtual clutch, and instead, a semi-clutch is used. The driver can arbitrarily set in the HMI20 whether to use the shift control according to this example or the shift control using blipping.

[0071] According to the time chart shown in FIG. 7, a downshift signal is input from the shift position sensor 14 to the control device 101 at time t31. In response to the input of the downshift signal, the virtual accelerator opening is changed from the user required opening to 0% at a predetermined change rate. In the example shown in FIG. 7, since the user required opening is already 0%, the virtual accelerator opening is maintained at 0%. During that time, the virtual clutch opening is maintained at the engagement opening, and the virtual gear stage is maintained at the current N stage. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, the virtual engine torque is maintained at a constant negative value, the virtual rotational speed decreases, and the required drive wheel torque increases greatly on the negative side.

[0072] At time t32, it is confirmed that the virtual accelerator opening is 0%. In response to this, the virtual clutch opening is changed from the engagement opening to the release opening at a predetermined change rate. During that time, the virtual accelerator opening is maintained at 0%, and the virtual gear stage is maintained at the current N stage. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, the virtual engine torque is maintained at a constant negative value, the virtual rotational speed decreases, and the required drive wheel torque changes to the positive side and increases to zero. Then, the deceleration (the rearward acceleration of the vehicle) occurring in the vehicle changes from an increase to a decrease.

[0073] At time t33, the change of the virtual clutch opening to the release opening is completed. In response to this, the virtual gear stage is switched from the current N stage to neutral. During that time, the virtual accelerator opening is maintained at 0%, and the virtual clutch opening is maintained at the release opening. By calculating the virtual accelerator opening, the virtual clutch opening, and the virtual gear stage in this way, the virtual engine torque is maintained at a constant negative value, the decreasing speed of the virtual rotational speed increases, and the required drive wheel torque is maintained at zero. Then, the deceleration decreases to zero.

[0074] At time t34, the set time elapses since the virtual gear stage was switched to neutral. In response to this, the virtual gear stage is switched to the driver's requested gear stage (N-1 stage in the example shown in Fig. 7). Also, in this example, since the allowable rotational speed difference is made larger than in the example using blipping, the rotational speed difference between the virtual rotational speed and the virtual input shaft rotational speed (N-1 stage rotational speed in the example shown in Fig. 7) converges to the allowable speed difference at time t34. In response to this, the virtual clutch opening is changed from the release opening to the engagement opening at a predetermined change rate. The change rate from the release opening to the engagement opening in this example is set lower than in the example using blipping in order to lengthen the half-clutch period. The virtual accelerator opening is maintained at 0% after time t34. By calculating the virtual accelerator opening, virtual clutch opening, and virtual gear stage in this way, the virtual engine torque is maintained at a constant negative value, but the virtual rotational speed changes from decreasing to increasing, and the required drive wheel torque increases significantly from zero to the negative side. Then, as the drive wheel torque increases on the negative side, the deceleration increases.

[0075] At time t35, the change of the virtual clutch opening to the engagement opening is completed. In response to this, the virtual accelerator opening is changed from 0% to the user-requested opening at a predetermined change rate. During that time, the virtual clutch opening is fixed in the engaged state, and the virtual gear stage is fixed to the requested gear stage. By calculating the virtual accelerator opening, virtual clutch opening, and virtual gear stage in this way, the virtual engine torque increases to the torque corresponding to the user-requested opening, and the virtual rotational speed changes to the rotational speed determined by the requested gear stage and the vehicle speed. Also, the required drive wheel torque changes from changing to the negative side to changing to the positive side. Then, after the direction of change of the required drive wheel torque changes, a shift shock in the longitudinal direction occurs in the electric vehicle 100, but its magnitude is kept low.

[0076] At time t36, the change of the virtual accelerator opening degree to the required opening degree is completed. As a result, the downshift requested by the driver for the electric vehicle 100 by operating the pseudo shifter 24 is completed. After the completion of the downshift, the virtual accelerator opening degree is set to the required opening degree, the virtual clutch opening degree is fixed in the engaged state, and the virtual gear stage is fixed to the required gear stage.

[0077] According to the above shift control, in response to the downshift operation of the pseudo shifter 24 by the driver, the virtual accelerator opening degree is forcibly set to 0% which is the fully closed opening degree, and the half clutch is started in accordance with the switching of the virtual gear stage to the required gear stage. For this reason, the virtual engine rotation speed does not increase in response to the operation of the driver's accelerator pedal 22, and the rotational speed difference between the virtual engine rotation speed and the virtual input shaft rotation speed of the virtual manual transmission quickly converges within a predetermined range due to the action of the half clutch. As a result, even when the driver performs a downshift operation with the accelerator pedal 22 depressed, the virtual engine rotation speed does not increase suddenly and the shift time does not become longer, and the shift can be completed without giving the driver a sense of discomfort.

[0078] 5. Others The shift control during upshift and the shift control during downshift executed in the electric vehicle according to the present embodiment are also applicable to an electric vehicle provided with a pseudo clutch pedal together with a pseudo shifter. When the driver desires assistance for the clutch operation, the operation of the pseudo clutch pedal by the driver may be invalidated and the virtual clutch opening degree calculated by the driver model may be used.

Explanation of symbols

[0079] 2 Batteries, 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, 22 Accelerator Pedal, 24 Virtual Shifter, 100 Electric Vehicle, 101 Control Device, 102 Processing Circuit, 103 Memory, MOD01 Vehicle Model, MOD10 Driver Model, MOD11 Engine Model, MOD12 Clutch Model, MOD13 Manual Transmission Model, MOD14 Axle - Driving Wheel Model

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 operation of a manual transmission internal combustion engine vehicle, a control device configured to change the relationship between the vehicle speed of the electric vehicle, the accelerator opening of the accelerator pedal, and the torque of the electric motor in response to an operation of the pseudo shifter, comprising: the control device includes: a memory storing a vehicle model in which a virtual vehicle is modeled; a processing circuit coupled to the memory and executing the vehicle model; the vehicle model includes: an engine model in which a virtual internal combustion engine is modeled; a clutch model in which a virtual clutch is modeled; a transmission model in which a virtual manual transmission is modeled; a driver model that calculates a virtual accelerator opening of the virtual internal combustion engine, a virtual clutch opening of the virtual clutch, and a virtual gear stage of the virtual manual transmission based on the accelerator opening, a shift position of the pseudo shifter, the vehicle speed, and a virtual engine rotational speed of the virtual internal combustion engine; the driver model is configured to: change the virtual accelerator opening from the accelerator opening to a fully closed opening in response to a change in the shift position due to an operation of the pseudo shifter; change the virtual clutch opening from an engaged opening to a disengaged opening in response to completion of the change of the virtual accelerator opening to the fully closed opening; change the virtual gear stage to a required gear stage corresponding to the changed shift position in response to completion of the change of the virtual clutch opening to the disengaged opening; change the virtual clutch opening from the disengaged opening to the engaged opening in response to convergence of a rotational speed difference between the virtual engine rotational speed and a virtual input shaft rotational speed of the virtual manual transmission within a predetermined range after the change of the virtual gear stage to the required gear stage; change the virtual accelerator opening from the fully closed opening to the accelerator opening in response to completion of the change of the virtual clutch opening to the disengaged opening. An electric vehicle characterized by the above.

2. In the electric vehicle according to Claim 1, when the operation of the pseudo shifter is a downshift operation, the driver model is configured to: temporarily increase the virtual accelerator opening from the fully closed opening in response to completion of the change of the virtual gear stage to the required gear stage; change the virtual clutch opening from the disengaged opening to the engaged opening in response to convergence of the rotational speed difference within the predetermined range. An electric vehicle characterized by...

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