阅读说明：本技术 电动车辆的用于生成虚拟换挡感觉的控制方法 (Control method for generating virtual gear shift feeling of electric vehicle ) 是由 吴智源 鱼祯秀 于 2020-12-08 设计创作，主要内容包括：本发明提供了一种电动车辆的用于生成虚拟换挡感觉的控制方法。所述方法包括生成电动车辆的虚拟换挡感觉,能够自由直接地改变和调节与虚拟换挡感觉的生成相关的变量,从而为驾驶员提供优选的虚拟换挡感觉。基于驾驶员预设的与换挡虚拟感觉的生成相关的变量值,根据驾驶员的驾驶输入值和车辆状况来生成虚拟换挡感觉,从而在驾驶没有多挡位变速器的电动车辆时模拟驾驶员在具有多挡位变速器的车辆中换挡时可以感觉到的多挡位换挡。(The invention provides a control method for generating a virtual gear shift feel of an electric vehicle. The method includes generating a virtual shift feel of the electric vehicle, enabling variables associated with the generation of the virtual shift feel to be freely and directly changed and adjusted, thereby providing the driver with a preferred virtual shift feel. The virtual shift feel is generated according to a driving input value of a driver and a vehicle condition based on a variable value preset by the driver in association with generation of the shift virtual feel, thereby simulating a multi-gear shift that the driver can feel when shifting gears in a vehicle having the multi-gear transmission when driving an electric vehicle without the multi-gear transmission.)

1. A control method of generating a virtual shift feel of an electric vehicle, comprising:

determining, by a controller, a base torque command in real time based on vehicle driving information collected from a vehicle during travel of an electric vehicle;

determining, by a controller, a virtual target gear based on vehicle driving information collected from a vehicle and driver setting information input by a driver;

determining gear shifting categories through a controller according to the virtual current gear and the determined virtual target gear, and selecting a virtual gear shifting intervention torque curve corresponding to the determined current gear shifting category from the virtual gear shifting intervention torque curves of each preset gear shifting category;

determining, by the controller in real time, a virtual shift intervention torque for generating a virtual shift feel according to the selected virtual shift intervention torque profile, and generating a final motor torque command using the determined base torque command, the virtual shift intervention torque, and driver set information input by the driver;

operation of a motor for driving the vehicle is regulated by the controller in accordance with the generated final motor torque command.

2. The control method of generating a virtual shift feel for an electric vehicle according to claim 1, wherein the first driver setting information includes at least one of: the number of gears, the shift schedule map that determines the virtual target gear from the vehicle driving information, and the lag between the up-down shifts.

3. The control method of generating a virtual shift feel for an electric vehicle according to claim 1, wherein the second driver setting information includes at least one of: the total shift time, the magnitude and form of the virtual shift intervention torque for the virtual shift intervention torque curve for each shift category, and the limit torque for each virtual gear used to limit the base torque command.

4. The control method of generating a virtual shift feel for an electric vehicle according to claim 1, further comprising:

calculating the limit torque of the current gear, a virtual transmission ratio corresponding to the virtual current gear, a preset virtual final transmission ratio and a limit torque setting parameter through a controller,

wherein, in generating the final motor torque command, if the basic torque command is greater than or equal to the calculated limit torque value, the final motor torque command is generated using the basic torque command having a value limited by the limit torque.

5. The control method of generating a virtual shift feel for an electric vehicle according to claim 4, wherein the second driver setting information includes at least one of: virtual final gear ratios and limit torque setting parameters for calculating a limit torque for each virtual gear that limits the base torque command.

6. The control method of generating a virtual shift feel for an electric vehicle according to claim 1, wherein the first driver setting information includes a virtual final gear ratio and a shift schedule map when determining the virtual target gear; determining a virtual vehicle speed as a reference speed based on an actual motor speed detected by a motor speed detector as vehicle travel information and a virtual final gear ratio in driver set information; and determines a virtual target gear based on the virtual vehicle speed and the vehicle load value determined by the shift schedule map in the driver setting information.

7. The control method of generating a virtual shift feel for an electric vehicle according to claim 6, wherein the shift schedule map includes:

a shift schedule map for an upshift used during the upshift; and

a shift schedule map for a downshift used during the downshift.

8. The control method of generating a virtual shift feel for an electric vehicle according to claim 1, further comprising:

determining a virtual vehicle speed through a controller according to an actual motor speed detected by a motor speed detector and a preset virtual final transmission ratio;

determining the virtual engine speed through a controller by using the determined virtual vehicle speed and the virtual transmission ratio information of the virtual current gear;

the determined virtual engine speed is displayed on the cluster board by the controller.

9. The control method of generating a virtual shift feel of an electric vehicle according to claim 8, wherein the virtual final gear ratio is driver setting information that is input in advance by a driver and set to the controller.

10. The control method of generating a virtual shift feel of an electric vehicle according to claim 8, wherein the value of the virtual engine speed scale for displaying the determined virtual engine speed on the cluster board is driver setting information that is previously input by a driver and set to the controller.

11. The control method of generating a virtual shift feel of an electric vehicle according to claim 1, wherein one or both of the information on the virtual idle speed, which is determined as a minimum value of a virtual engine speed for simulating engine idling of the internal combustion engine vehicle, and the information on the magnitude and period of the vibration torque command, which is a motor torque command that causes the motor to generate the vibration torque during the virtual idle, are driver setting information that is input in advance by a driver and set to the controller.

12. The control method of generating a virtual shift feel for an electric vehicle according to claim 1, further comprising:

determining a virtual vehicle speed through a controller by using an actual motor speed detected by a motor speed detector and a preset virtual final reduction transmission ratio;

determining the virtual engine speed through a controller by using the determined virtual vehicle speed and the information of the virtual transmission ratio of the virtual current gear;

comparing the determined virtual engine speed with a set threshold speed through a controller, and determining that the virtual engine enters a virtual red area through the controller when the virtual engine speed is greater than or equal to the threshold speed;

in a state where entry into the virtual red region is determined, a torque command for reducing the virtual engine speed to a target threshold speed is generated by the controller to perform virtual fuel cut control for adjusting the operation of the motor.

13. The control method of generating a virtual shift feel for an electric vehicle according to claim 12, wherein the controller is configured to regulate the operation of the electric machine during virtual fuel cut control using a torque command that sums up torque fluctuations at the time of fuel cut, the torque fluctuations having a magnitude and a period set in the torque command for reducing the virtual engine speed.

14. The control method of generating a virtual shift feel of an electric vehicle according to claim 13, wherein at least one of a magnitude and a period of the torque fluctuation during the fuel cut is driver setting information that is input in advance by a driver and set to the controller.

15. The control method of generating a virtual shift feel for an electric vehicle according to claim 12, wherein at least one of the virtual final gear ratio and the threshold rotational speed is driver setting information that is input in advance by a driver and set to the controller.

16. The control method of generating a virtual shift feel of an electric vehicle according to claim 1,

the virtual shift intervention torque curve for each shift category is one of the driver set information that the driver has previously entered and set to the controller,

the magnitude and form of the virtual shift intervention torque corresponding to each shift category is set by the driver.

17. The control method of generating a virtual shift feel for an electric vehicle according to claim 1, wherein the driver setting information is input through an in-vehicle interface connected to the controller or a mobile device communicatively connected to the controller.

Technical Field

The present invention relates to a control method of an electric vehicle, and more particularly to a control method of an electric vehicle capable of generating and achieving the same shift feeling as that of a vehicle equipped with a multi-speed transmission in an electric vehicle not having the multi-speed transmission.

Background

As is well known, an Electric Vehicle (EV) is a vehicle that is driven using a motor as a driving force source for driving the vehicle. A power train of an electric vehicle includes a battery that supplies electric power to drive a motor, an inverter connected to the battery to drive and operate the motor, the motor connected to the battery through the inverter as a driving source of the vehicle to perform charging and discharging, and a reduction gear that reduces a rotational force of the motor and transmits the rotational force to driving wheels.

Specifically, when the motor is driven, the inverter converts Direct Current (DC) supplied from the battery into Alternating Current (AC) and applies the AC to the motor through a wire, and when the motor is regenerated, the inverter converts alternating current generated by the motor operating as a generator into direct current supplied to the battery, and thus the inverter operates so that the battery is charged. Further, unlike conventional internal combustion engine vehicles, ordinary electric vehicles do not use a multi-speed transmission, but provide a reduction gear having a fixed gear ratio between the electric motor and the drive wheels.

The reason is that the internal combustion engine has a wide energy efficiency distribution range with respect to an operating point and can provide high torque only in a high speed region, whereas in the case of the motor, an efficiency difference with respect to the operating point is relatively small and low-speed high torque can be achieved only by unique characteristics of the motor. A significant advantage is that without a transmission, smooth operability can be provided without interruption of drivability due to shifting. However, for a driver who wishes to get pleasure in driving, the absence of a transmission and a gear change sensation can be boring to the driver.

Therefore, in an electric vehicle that does not have a multi-speed transmission and is equipped with a reduction gear, a technique is required that enables a driver to experience the driving feeling, fun, excitement, and direct-connection feeling that are provided by a vehicle equipped with a multi-speed transmission. Further, if a method of customizing the virtual shift feel can be provided to a driver who attaches importance to the driving feel, a more distinctive interesting feature can be highlighted.

Disclosure of Invention

Accordingly, the present invention provides an electric vehicle control method capable of generating and achieving the same shift feeling as that of a vehicle equipped with a multi-speed transmission in an electric vehicle without the multi-speed transmission.

In addition, the present invention provides a control method for generating a virtual gear shift feel of an electric vehicle, which is capable of freely changing and adjusting the set value of a variable (i.e., some predetermined driver setting information) related to the generation of the virtual gear shift feel, so that the driver can be provided with a virtual gear shift feel personally preferred by the driver.

To achieve the object, according to an exemplary embodiment of the present invention, a control method of generating a virtual gear shift feel of an electric vehicle may include: determining, by a controller, a base torque command in real time based on vehicle driving information collected from a vehicle during travel of an electric vehicle; determining, by a controller, a virtual target gear based on vehicle driving information collected from a vehicle and driver setting information input by a driver; determining, by the controller, a gear shift category according to the virtual current gear and the determined virtual target gear, and selecting a virtual gear shift intervention torque curve corresponding to the determined current gear shift category from the virtual gear shift intervention torque curves of each preset gear shift category; determining, by the controller in real time, a virtual shift intervention torque for generating a virtual shift feel according to the selected virtual shift intervention torque profile, and generating a final motor torque command using the determined base torque command, the virtual shift intervention torque, and driver set information input by the driver; operation of a motor for driving the vehicle is controlled by the controller according to the generated final motor torque command.

Therefore, according to the electric vehicle control method of the invention, it is possible to generate and realize the same shift feeling as that of a vehicle equipped with a multi-speed transmission in an electric vehicle not having the multi-speed transmission. In addition, the variables related to the generation of the virtual shift feeling can be directly changed and adjusted, so that the driver can be provided with the virtual shift feeling that the driver himself prefers. In other words, the driver can directly change and adjust the value of the variable related to the generation of the virtual shift feel, and can be provided with the virtual shift feel generated by the changed and adjusted variable value.

Drawings

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

fig. 1 is a block diagram showing a configuration of an apparatus for controlling an electric vehicle according to the present invention.

FIG. 2 is a block diagram showing the input and output variables and virtual shift intermediate variables of the virtual shift model of the present invention for implementing a virtual shift function.

Fig. 3 is a flowchart illustrating a process of the present invention for implementing a virtual shift function.

Fig. 4 is a diagram showing a shift schedule map for determining a virtual target gear of the present invention.

Fig. 5 is a diagram showing a shift schedule map usable for upshifts and downshifts of the present invention.

Fig. 6 is a graph showing a maximum motor torque curve depending on the motor rotation speed and a limit torque of each virtual gear, which is calculated by reflecting gear ratio information, according to the present invention.

FIG. 7 is a graph illustrating an example of a virtual shift intervention torque curve of the present invention.

Fig. 8 is a diagram showing a shift state and a vehicle behavior state during virtual shifting according to the present invention.

Fig. 9 is a flowchart showing a process of inputting and using driver setting information of the present invention.

Fig. 10 and 11 are diagrams showing examples of virtual shift intervention torque curves depending on the virtual transmission type of the present invention.

Fig. 12 and 13 are diagrams illustrating the method of personalizing the form of the virtual shift intervention torque according to the driver's favorite virtual transmission type of the present invention.

Fig. 14 is a diagram showing an example of a long drive setting of the virtual final drive ratio of the invention.

Fig. 15 is a diagram showing an example of a short drive setting of virtual final drive ratio rFg of the present invention.

Fig. 16 to 18 are diagrams showing predetermined shift schedule maps selectable by the driver of the present invention.

Fig. 19 and 20 are diagrams showing examples of the hysteresis setting of the shift schedule map of the invention.

Detailed Description

It should be understood that the term "vehicle" or "vehicular" or other similar terms as used herein generally includes motor vehicles such as passenger automobiles including Sport Utility Vehicles (SUVs), buses, vans, various commercial vehicles, watercraft including various boats, ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from non-fossil energy sources). As referred to herein, a hybrid vehicle is a vehicle having two or more power sources, such as a gasoline-powered vehicle and an electric-powered vehicle.

While the exemplary embodiments are described as performing an exemplary process using multiple units, it should be understood that the exemplary process may also be performed by one or more modules. Further, it should be understood that the term controller/control unit means a hardware device including a memory and a processor, and is specifically programmed to perform the processes described herein. The memory is configured to store modules that the processor is specifically configured to execute to perform one or more processes described further below.

Furthermore, the control logic of the present invention may be embodied as a non-transitory computer readable medium on a computer readable medium, which includes executable program instructions executed by a processor, controller/control unit, or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, Compact Disc (CD) -ROM, magnetic tape, floppy disk, flash drive, smart card, and optical data storage device. The computer readable recording medium CAN also be distributed over network coupled computer systems so that the computer readable medium is stored and executed in a distributed fashion, such as through a telematics server or Controller Area Network (CAN).

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, values, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, values, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Unless specifically stated or otherwise apparent from the context, the term "about" as used herein is understood to be within the normal tolerance of the art, e.g., within 2 standard deviations of the mean. "about" can be understood to be within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from the context, all numbers provided herein are modified by the term "about".

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. However, the present invention is not limited to the embodiments described herein, and may be embodied in other forms.

An object of the present invention is to provide a control method of an electric vehicle capable of generating and realizing a multi-range shift feel identical to that of a vehicle equipped with a multi-range transmission in an electric vehicle not having the multi-range transmission. In particular, it is another object of the present invention to provide a control method for generating a virtual gear shift feel of an electric vehicle, which is capable of freely changing and adjusting a variable value related to the generation of the virtual gear shift feel, so that the driver can be provided with the virtual gear shift feel personally preferred by the driver.

In the following description, the motor refers to a driving motor that drives a vehicle, and in the present invention, the vehicle to be controlled may be an electric vehicle equipped with a reduction gear without an internal combustion engine (i.e., a general-purpose engine) and a multi-speed transmission. As described above, in the case of a pure electric vehicle driven by a motor (i.e., a motor-driven vehicle), unlike a conventional internal combustion engine vehicle, the pure electric vehicle does not use a multi-speed transmission, but a reduction gear using a fixed gear ratio is provided between the motor and drive wheels.

However, when there is no multi-speed transmission, there is an advantage in that operation is smooth without interrupting drivability when shifting gears, but when the driver desires a driving feeling, fun, excitement, direct connection feeling, or the like, which the multi-speed transmission provides, the driver feels bored while driving. Therefore, in an electric vehicle equipped with a reduction gear instead of a multi-speed transmission, a technique is required that enables a driver to experience a driving feeling, fun, excitement, direct-connection feeling, and the like, which are provided by the multi-speed transmission.

As in the present invention, when a driver desires to experience a driving feeling, fun, excitement, direct connection feeling, etc., which can be provided only by a transmission, if a function of realizing a virtual shift feeling is provided so that the driver can experience the desired feeling and fun on the same vehicle without having to change the vehicle, the commercial value of the vehicle can be improved and distinguished.

In addition, in conventional electric vehicles, it is not possible for the driver to control the gear, so only speed and accelerator pedal inputs can be used to adjust the behavior of the vehicle. However, if the function of the virtual shift feeling is realized in the vehicle capable of high-performance sport driving, it may be helpful to manage the turning entry speed, the load transmission, and the like at the time of driving.

Further, if a method of customizing the virtual shift feel can be provided to a driver who attaches importance to the driving feel, a more distinctive interesting feature can be highlighted. In particular, the personalization of the shift feel means that the driver directly changes and adjusts the set value of the variable related to the generation of the virtual shift feel, thereby generating the virtual shift feel corresponding to the changed set value.

Existing internal combustion engine vehicles are limited in achieving personalization of the powertrain due to fuel efficiency, exhaust regulations, and the like. However, since electric vehicles do not have such exhaust regulations, and personalization of the drive system has relatively less impact on fuel economy than internal combustion vehicles, if virtual shift feel can be actively personalized, vehicle quality can be improved from an emotional standpoint.

Therefore, there is a need for a method of implementing virtual multi-range shifting in an electric vehicle without a multi-range transmission, and a method capable of implementing personalization according to driver's desire when implementing a virtual shift feel of an electric vehicle powertrain through a virtual shift function that simulates multi-range shifting. Accordingly, a motor control method is disclosed in which a virtual shift model is established and a multi-gear shift feel can be achieved using the model. In addition, a control method is disclosed in which the driver can directly change the set value of a variable related to the generation of the virtual shift feeling.

The invention is characterized in that the virtual shift intervention torque and the limit torque of each virtual gear can be determined from input variables by means of a virtual shift model which uses as input vehicle driving information collected from the vehicle during driving and which can then operate the electric machine with the determined virtual shift intervention torque, the determined limit torque of each virtual gear and the electric machine torque command, thereby achieving a virtual multiple gear shift.

In the present invention, the virtual shift function may include generating a virtual shift feel according to a driving input value of the driver and a vehicle condition based on a variable value preset by the driver in association with generation of the virtual shift feel, thereby simulating a multi-gear shift that the driver may feel when shifting gears in a vehicle having the multi-gear transmission when driving an electric vehicle not having the multi-gear transmission.

In the present invention, the virtual shift feel may be a simulation of the behavior and motion of the vehicle that the driver can feel during shifting of the multi-speed transmission, and in the present invention, the virtual shift feel may be generated and realized by the control of the drive motor. In particular, the multi-speed transmission may be one of an Automatic Transmission (AT), a Dual Clutch Transmission (DCT), and an Automatic Manual Transmission (AMT). In the present invention, a virtual shift feel is provided by generating and simulating the vehicle behavior and motion exhibited by a vehicle equipped with one of these transmissions during a shift, via control of the drive motors.

Fig. 1 is a block diagram showing a configuration of an apparatus for controlling an electric vehicle according to the present invention, and fig. 2 is a block diagram showing input and output variables and a virtual shift intermediate variable of a virtual shift model for implementing a virtual shift function of the present invention. Further, fig. 3 is a flowchart showing a procedure for realizing the virtual shift function of the present invention. The control method according to the invention may include a virtual shift method that generates and implements a virtual shift feel simulating a multi-speed shift of a conventional multi-speed transmission vehicle through control or operation of an electric motor during running of the vehicle.

Referring to fig. 3, the control method according to the present invention may include: the method includes steps S11, S12, S13 and S14, wherein the step S11 determines whether a virtual shift function is turned on, the step S12 calculates a basic torque command in real time when the virtual shift function is turned on, the step S13 determines a virtual shift intermediate variable value through input variables in a virtual shift model, and the step S14 determines a basic torque command limited by a limit torque of each virtual gear (i.e., a limit torque of a current gear).

In addition, the control method according to the present invention may further include: step S15, step S16, step S17, and step S18, the step S15 determining whether or not the virtual red region has been entered by the virtual engine speed, the step S16 performing the virtual fuel cut control when it is determined that the virtual red region has been entered, the step S17 determining a final motor torque command by adding the virtual shift intervention torque to the basic torque command, and the step S18 performing the motor control according to the final motor torque command.

Describing a device configuration for performing the above-described virtual shift process, as shown in fig. 1, the device for controlling according to the present invention may include: an interface section 11, a driving information detector 12 (e.g., a sensor), a first controller 20, and a second controller 30; the interface section 11 allows the driver to select and input one of virtual shift functions of turning on and off the vehicle and input predetermined driver setting information; the driving information detector 12 is configured to detect vehicle driving information; the first controller 20 is configured to generate and output a torque command based on the vehicle driving information detected by the driving information detector 12 and the driver setting information input through the interface portion 11; the second controller 30 is configured to operate the driving device 41 in accordance with the torque command output from the first controller 20.

In the following description, the controller is divided into the first controller 20 and the second controller 30, but a plurality of controllers or a single integrated control element are collectively referred to as a controller, and it is also understood that a control process is performed by the controller according to the present invention. As the interface section 11, any device may be utilized as long as the driver can turn on and off the virtual shift function of the vehicle and input predetermined driver setting information, and for example, an operation device (e.g., buttons and switches) provided in the vehicle, and other input devices of an AVN (audio, video, navigation) system, a touch panel, or the like may be used.

The interface part 11 may be connected to the first controller 20, and then, when there is an input operation of the driver inputting an opening operation or a closing operation and the driver setting information, an opening operation signal and a closing operation signal from the interface part 11 and the input operation signal may be input to the first controller 20. Thus, the first controller 20 may be configured to recognize the on operation state or the off operation state of the virtual shift function by the driver and the input state of the driver setting information.

In the present invention, the virtual shift function that generates and implements the virtual shift feel during the running of the vehicle is performed only in response to the reception of the on input of the virtual shift function by the driver through the interface section 11 (see step S11 in fig. 3). In addition, when the above-described interface section 11 is a vehicle input device provided in a vehicle, although not shown in fig. 1, the driver can perform the on operation and the off operation of the virtual shift function and input the driver setting information by a moving device (not shown) instead of using the vehicle input device.

The mobile device must be communicatively connected to the in-vehicle device (e.g., the first controller), and for this purpose, an input/output communication interface (not shown) that establishes communication between the mobile device and the first controller 20 may be utilized. The driving information detector 12 may be configured to detect vehicle driving information necessary for generating a motor torque command in the vehicle, wherein the vehicle driving information may include driving input information of a driver and vehicle state information.

In an exemplary embodiment of the present invention, the driving information detector 12 may include an accelerator pedal detector configured to detect accelerator pedal input information according to an accelerator pedal operation of the driver, and a brake pedal detector configured to detect brake pedal input information according to a brake pedal operation of the driver. Further, the driving information detector 12 may include a shift paddle and a shift lever detector and a motor rotation speed detector configured to detect a rotation speed of a motor (hereinafter referred to as "motor rotation speed") as the driving device 41 for driving the vehicle.

In particular, the accelerator pedal detector may be a general accelerator pedal sensor (i.e., an accelerator pedal position sensor, APS) mounted on an accelerator pedal and configured to output an electric signal based on an accelerator pedal operation state of a driver. The brake pedal detector may be a general Brake Pedal Sensor (BPS) mounted on a brake pedal and configured to output an electric signal based on a brake pedal operation state of a driver. In addition, the motor rotation speed detector may be a known resolver installed in the motor (i.e., the drive motor) 41.

At this time, the driving input information of the driver may include an accelerator pedal input value (APS value) detected by an accelerator pedal detector and a brake pedal input value (BPS value) detected by a brake pedal detector. In addition, the driving input information of the driver may further include: inputting information according to a shift paddle operated by a shift paddle of a driver; and shift lever input information (i.e., information of P-range, R-range, N-range, and D-range) according to a shift lever operation of the driver.

The shift lever input information may be detected by a shift lever detector and the shift paddle input information may be received by the first controller 20 from the shift paddle. Further, the vehicle state information may include the motor rotation speed detected by the motor rotation speed detector. The driving information used in the torque command generator 21 to generate the basic torque command may further include a vehicle speed as vehicle state information, and in this case, the driving information detector 12 is not shown in fig. 1, but may further include a vehicle speed detector configured to detect a current running vehicle speed, and the vehicle speed detector may be configured to include a wheel speed sensor installed in a driving wheel of the vehicle.

In addition, the first controller 20 may include: a torque command generator 21, a virtual shift controller 22, and a final torque command generator 23; the torque command generator 21 is configured to generate a basic torque command from vehicle driving information; the virtual shift controller 22 is configured to generate a correction torque command for generating and implementing a virtual shift feel (i.e., a virtual shift intervention torque command for implementing a virtual shift feel) from the vehicle driving information according to the driver setting information; the final torque command generator 23 is configured to correct the base torque command with the corrected torque command to generate a corrected final torque command.

The base torque command may be a motor torque command determined and generated based on driving information collected during running of the ordinary electric vehicle (step S12), and the torque command generator 21 may be a Vehicle Controller (VCU) or a part of a vehicle controller configured to generate the motor torque command based on the driving information in the ordinary electric vehicle. Further, in the present invention, the virtual shift controller 22 is a novel component configured to determine, generate and output a virtual shift intervention torque command (which is a corrective torque command separate from the base torque command, used only to achieve a virtual shift feel), and may be added as part of the vehicle controller interior, or may be provided as a separate control component from the vehicle controller.

In the final torque command generator 23, the basic torque command input from the torque command generator 21 may be corrected by the corrective torque command input from the virtual shift controller 22, but the final torque command may be calculated by adding the virtual shift intervention torque command as the corrective torque command to the basic torque command. The second controller 30 is a controller configured to receive a torque command transmitted from the first controller 20 (i.e., a final torque command determined by the final torque command generator 23 of the first controller 20 to operate the driving device 41). In the present invention, the driving device 41 is a motor that drives the vehicle (i.e., a driving motor), and the second controller 30 is a known motor controller (i.e., a motor control unit, MCU) and is configured to drive and operate the motor using an inverter in a general electric vehicle.

Meanwhile, in the present invention, a virtual shift model that determines and outputs a virtual shift intervention torque command using vehicle driving information collected from the vehicle as an input may be set and input to the virtual shift controller 22. In the present invention, the input variables of the virtual shift model become the vehicle driving information detected by the driving information detector 12, and the vehicle driving information includes the driver's driving input information and the vehicle state information as described above.

In particular, the driver's driving input information may include accelerator pedal input information (i.e., information of APS value), brake pedal input information (i.e., information of BPS value), shift pad input information, and shift lever input information (i.e., information of P-range, R-range, N-range, and D-range). Additionally, the vehicle state information may include a motor speed. In the virtual shift controller 22, the values of intermediate variables can be calculated from the model input variables by the virtual shift model, and further, torque commands for generating and implementing virtual shift feel and limit torque reflecting gear ratio information for each virtual gear are determined and output from the values of these intermediate variables (see step S13). In particular, the torque command for generating and realizing the virtual shift feel becomes not only the virtual shift intervention torque command but also the correction torque command for correcting the base torque command.

Referring to fig. 2, as the vehicle driving information, the input variables of the virtual shift model M may include: accelerator pedal input information (information of APS value); brake pedal input information (information of BPS value); inputting information by a gear shifting plectrum; the shift lever inputs information (information of a P-gear, an R-gear, an N-gear, and a D-gear); and motor speed omega M information. In addition, intermediate variables for executing the virtual shift function in the virtual shift model M, i.e., model intermediate variables for generating the virtual shift feel obtained from the input variables in the virtual shift model, are shown in fig. 2.

In an exemplary embodiment of the present invention, the intermediate variables obtained from the input variables may include: the virtual speed SpdVir, the virtual speed for downshift SpdVirDn, the virtual target gear position TarGe, the virtual manual shift mode target gear position TarGeMan, the virtual current gear position CurGe, the virtual gear engine speed omega vir, the gear ratio rG1, rG2, … …, rGi, the virtual final gear ratio rFg, the target input speed omega tar based on the virtual target gear position, the target input speed omega cur based on the virtual current gear position, and the virtual shift schedule xproges.

In particular, when it is assumed that a virtual transmission and a virtual engine are present in the vehicle, the "input speed" refers to a virtual engine speed that becomes an input speed of the virtual transmission. Thus, the "target input speed based on the virtual target gear" refers to the virtual engine speed of the virtual target gear, and the "target input speed based on the virtual current gear" refers to the virtual engine speed of the virtual current gear. In the present invention, the intermediate variables used for virtual shifting are independent of the physical values of the vehicle's actual hardware, and are used only to achieve a virtual shift feel.

In the present invention, physical variables used as actual measurements or interventions in the powertrain of an electric vehicle may be referred to as the above-described input variables (APS value, BPS value, shift paddle input value, and shift lever input value), motor rotation speed omega m, virtual shift intervention torque tqltv, and limit torque tqLmt for each virtual gear. Further, in an exemplary embodiment of the present invention, the output variables of the virtual shift model M may include a virtual shift intervention torque command (i.e., a corrective torque command) tqltv for providing and implementing a virtual shift feel.

In addition, the output variables of the virtual shift model M may further include a limit torque tqLmt for each virtual gear. Furthermore, in an exemplary embodiment of the present invention, the output variables of the virtual shift model M may further include at least some virtual shift intermediate variables, for example, may further include a virtual target gear TarGe, a virtual current gear CurGe, and a virtual engine speed omega vir among the virtual shift intermediate variables.

The virtual target gear TarGe, the virtual current gear CurGe, and the virtual engine speed omega vir output from the virtual shift model M may be transmitted to an instrument cluster controller (not shown) and may become instrument cluster display information displayed on an instrument cluster (not shown). The virtual shift intervention torque command output from the virtual shift controller 22 and the limit torque of each virtual gear (which is the limit torque of the current gear) are input to the final torque command generator 23, and then the final torque command can be generated from the basic torque command using the final torque command generator 23.

In other words, in the final torque command generator 23, the basic torque command may be limited to the limit torque of each virtual gear as necessary (step S14), wherein when the basic torque command is smaller than the limit torque, the basic torque command may be used as it is, and when the basic torque command is larger than the limit torque, the basic torque command may be limited to the limit torque value. Therefore, in the final torque command generator 23, the basic torque command limited to a value within the limit torque of each virtual gear may then be added to the virtual shift intervention torque command, and the added torque command becomes the final motor torque command (step S17).

When the base torque command is greater than or equal to the limit torque, the final electric machine torque command may be determined by summing the limit torque value and the virtual shift intervention torque command. In this regard, the final motor torque command calculated in the final torque command generator 23 may be sent to the second controller 30, and the second controller 30 may be configured to operate the motor according to the final motor torque command (step S18).

Hereinafter, the virtual shift intermediate variables of the virtual shift model M in the virtual shift controller 22 will be described in more detail. First, in the virtual shift model M of the virtual shift controller 22, a virtual vehicle speed SpdVir is generated as an input of the shift plan map, and this virtual vehicle speed SpdVir is used as a reference vehicle speed in the virtual shift function. By using the actual motor speed omega m and the virtual final gear ratio rFg (which are some of the model input variables), the virtual vehicle speed SpdVir can be calculated as a value that is directly proportional to the actual motor speed omega m.

In the example of fig. 2, the virtual final gear ratio is shown as being included in the virtual shift intermediate variable. However, in an exemplary embodiment of the present invention, the virtual final gear ratio rFg may be one of the driver settings that the driver has predetermined. Further, in the virtual shift model, a virtual vehicle speed SpdVirDn for downshift, which is a variable used as an input of the shift plan map during downshift, is generated, and thus is calculated by applying a preset scale factor and a compensation value to the virtual vehicle speed spdvirdr.

However, when the shift schedule maps for the upshift and the downshift are provided and used, respectively, it is no problem to use only the virtual vehicle speed SpdVir as the reference speed. When a single shift schedule map is used without distinguishing between upshifts and downshifts, the virtual vehicle speed SpdVirDn for downshifts is further used in addition to the virtual vehicle speed SpdVir as the reference vehicle speed to add a hysteresis effect between upshifts and downshifts. In order to achieve the usual hysteresis effect in the present invention, the virtual vehicle speed SpdVirDn for downshift may be determined as a value obtained by adding the positive compensation value to the above-described product value after multiplying the virtual vehicle speed SpdVir by a scale factor larger than 1.

Fig. 4 is a diagram showing a shift schedule map for determining the virtual target gear TarGe of the invention, and shows a shift schedule map for an upshift and a shift schedule map for a downshift, which are separately provided. In each of the illustrated shift schedule maps, the horizontal axis represents the vehicle speed (km/h) and the vertical axis represents the accelerator pedal input value (APS value), at which time the vehicle speed on the horizontal axis is the virtual vehicle speed SpdVir as the reference vehicle speed.

As described above, the shift schedule map uses the virtual vehicle speed SpdVir and the accelerator pedal input value (APS value) indicating the driver's intention, and determines the virtual target gear position TarGe corresponding to the virtual vehicle speed SpdVir and the accelerator pedal input value (APS value) from the shift schedule map. As shown in the cluster, when the shift plan map for upshift and the shift plan map for downshift are respectively provided, the virtual vehicle speed is used as the vehicle speed for determining the virtual target gear position TarGe, and at this time, the virtual vehicle speed is the virtual vehicle speed SpdVir obtained from the actual motor rotational speed omega m and the virtual final gear ratio rFg as the reference speed as described above.

As described above, the virtual target gear stage TarGe is determined from the virtual vehicle speed SpdVir and the accelerator pedal input value (APS value) as the reference vehicle speed, when the shift schedule map for upshift and the shift schedule map for downshift are used, respectively. However, when a single shift plan map is used for the upshift and the downshift, the virtual vehicle speed SpdVir for the downshift is used separately from the virtual vehicle speed SpdVir as the reference vehicle speed to determine the virtual target gear TarGe.

Fig. 5 is a diagram showing a shift schedule map usable for upshifts and downshifts of the present invention. When a single shift plan map shown in fig. 5 is used for upshifts and downshifts, the virtual vehicle speed SpdVir that is the reference vehicle speed (becomes the virtual vehicle speed for upshifts) is used in the case of upshifts, and the virtual vehicle speed SpdVirDn that is used for downshifts is used in the case of downshifts, whereby the virtual target gear position TarGe in the shift plan map is determined.

In other words, by using one shift schedule map, at the time of upshift, the virtual target gear position TarGe is determined from the virtual vehicle speed SpdVir and the accelerator pedal input value (APS value) as the reference vehicle speed, and at the time of downshift, the virtual target gear position TarGe is determined from the virtual vehicle speed SpdVirDn and the accelerator pedal input value (APS value) for downshift. In other words, in the shift schedule map of fig. 5, the vehicle speed on the horizontal axis is the virtual vehicle speed SpdVir as the reference speed at the time of the vehicle upshift, and the vehicle speed on the horizontal axis is the virtual vehicle speed SpdVirDn for the downshift at the time of the vehicle downshift.

In the above description, although the vertical axis of fig. 4 and 5 is described as the accelerator pedal input value, i.e., the APS value (%), other vehicle load values may be used as the vertical axis value of the shift schedule map instead of the accelerator pedal input value. In other words, the vertical axis of the shift schedule map may be the brake pedal input value (BPS value) or the base torque command, rather than the accelerator pedal input value.

Along with this virtual vehicle speed, input variables of the shift schedule map for determining the virtual target gear can also be present. When the virtual vehicle speed SpdVir that is the reference vehicle speed is the virtual vehicle speed for the upshift, the virtual vehicle speed SpdVirDn for the downshift may be determined by multiplying the virtual vehicle speed SpdVir for the upshift by the scale factor α and then adding the compensation value β, as shown in equation 1 below.

SpdVirDn＝SpdVir×α+β(1)

Next, in the virtual shift model M of the virtual shift controller 22, it may be determined whether or not the manual shift mode is entered, but when an operation of a shift lever or an input of a shift paddle occurs, it may be determined that the manual shift mode in which shifting is performed according to the driver's intention is operated, and otherwise, a general automatic shift in which shifting is automatically performed according to a preset shift schedule is operated.

Since the target gear according to the driver's intention may be different from the target gear at the time of automatic shifting, in response to determining that the manual shift mode is operated, the target gear in the manual shift mode, that is, the virtual manual shift mode target gear TarGeMan, may be determined in the virtual shift model M of the virtual shift controller 22. The virtual manual shift mode target gear TarGeMan may be determined by shift lever input information or shift paddle input information of the driver.

In addition, a final target gear in the virtual shift function may be calculated from the virtual shift model M of the virtual shift controller 22. As described above, basically, in the automatic shift mode, the target gear determined by the shift schedule map may be determined as the virtual target gear TarGe, but in the manual shift mode, the virtual manual shift mode target gear TarGeMan determined by the driver's shift lever input or shift paddle input may be determined as the virtual target gear TarGe.

Explaining how the target gear is determined by the shift schedule map as described above in the automatic shift mode (i.e., when not in the manual shift mode), the shift schedule map having load value inputs such as the virtual vehicle speed (km/h), the accelerator pedal input value (APS value), and the like is used. Specifically, the shift schedule map is a map in which a virtual target shift range is set in advance, the virtual target shift range corresponds to each combination of inputs of vehicle load value information (including a virtual vehicle speed, an accelerator pedal input value, and the like), and for the vehicle load value information, a brake pedal input value (BPS value), a basic torque command, or the like may be used in addition to an accelerator pedal input value (APS value) as driving input information of the driver.

For the reference speeds used as the inputs of the shift schedule map as described above, a virtual vehicle speed SpdVir determined by the virtual final gear ratio rFg and the actual motor rotation speed omega m may be used, or a virtual vehicle speed SpdVirDn for downshift determined from the virtual vehicle speed may be used. In determining the target gear as described above, at the present point in time, there are two target gears, i.e., two target gears determined by the virtual vehicle speed SpdVir as the reference speed and the virtual vehicle speed SpdVirDn for downshift, respectively.

At this time, the final target gear may be determined using two values, wherein, as a method thereof, only when the value of the target gear determined by the virtual vehicle speed SpdVir increases compared to the value in the previous step (for example, from the first gear to the second gear) is determined as a valid value, the target gear determined by the virtual vehicle speed SpdVir is determined, and is updated to the final virtual target gear TarGe.

In the same manner, the target gear determined by the virtual vehicle speed for downshift SpdVirDn may be determined as the valid value only when the value of the target gear determined by the virtual vehicle speed for downshift SpdVirDn is reduced (e.g., from the second gear to the first gear) from the value in the previous step, so that the target gear determined by the virtual vehicle speed for downshift SpdVirDn may be determined and updated to the final virtual target gear TarGe. However, the virtual target gear TarGe that is finally determined should be calculated as a value within a selectable range of the lowest gear and the highest gear.

Meanwhile, in the virtual shift model of the virtual shift controller 22, a delay target gear having a delay value delayed from the virtual target gear TarGe by a predetermined delay time, which represents a time at which a shift is made to change to the target gear but the shift of the virtual engine speed omega vir has not yet been started, using a preset time, may be determined. The delay time is the time involved in the state before the inertia phase begins on the actual transmission. In addition, the virtual shift model M of the virtual shift controller 22 detects a change in the target gear TarGe to calculate a virtual shift schedule xproges.

In particular, the change of the target gear indicates that in the manual shift mode a new virtual target gear is determined which is different from the current gear according to the shift plan map or the shift paddle input information or the shift lever input information. When the target gear is changed (i.e. when a new virtual target gear is determined), timing starts from time 0, and a shift schedule xProgress can be determined as a percentage of the timing time compared to the total preset shift time, wherein the shift schedule xProgress is increased up to 100%.

The time point at which the target gear is changed refers to a time point at which a new virtual target gear is determined from a shift schedule map of a virtual current gear, which is a previous target gear. As described above, the time counting can be started by setting the time point at which the target shift position is changed to time 0, but a time point at which the change of the target shift position is delayed may be used instead as the time counting start time.

In other words, when the changed virtual target gear is determined, the controller may be configured to count the time from the time when the delay time has elapsed after the virtual target gear is determined, and to use the counted time to determine the virtual shift schedule in the same manner. Alternatively, as another approach, the value of the current virtual engine speed during the shift may be expressed as a percentage that represents: the engine speed value obtained in real time is located at a position between the target input speed based on the virtual current gear (i.e., the virtual engine speed in the virtual current gear) omega cur and the target input speed based on the virtual target gear (i.e., the virtual engine speed in the virtual target gear) omega tar.

In determining the virtual target gear, the virtual shift schedule may be determined as: the speed difference between the real-time virtual engine speed omega Vir and the target input speed omega Cur based on the virtual current gear during the gear shifting process is relative to the percentage value of the speed difference between the target input speed omega Tar based on the virtual target gear and the target input speed omega Cur based on the virtual current gear during the gear shifting process. In addition, in the virtual shift model M of the virtual shift controller 22, the virtual engine speed omega cur can be determined using the information of the virtual vehicle speed SpdVir (which is essentially the reference speed) and the virtual gear ratio rGi of the virtual current gear.

The virtual engine speed omega cur may be obtained from a product of a virtual vehicle speed SpdVir of the virtual current gear and the virtual gear ratio rGi, or the virtual engine speed omega cur may be obtained from a product of a power train speed (e.g., a motor speed) and the virtual gear ratio rGi of the virtual current gear. In addition, during a shift from when the target gear is changed (i.e., when the shift is started), the virtual engine speed omega vir may be determined from information based on the target input speed (i.e., the virtual engine speed of the virtual current gear) omega curr based on the virtual current gear and the target input speed (i.e., the virtual engine speed of the virtual target gear) omega tar based on the virtual target gear.

In particular, when the target gear is changed, the virtual vehicle speed SpdVir of the virtual current gear CurGe and the virtual gear ratio rGi may be used to obtain the target input speed omega cur based on the virtual current gear. In addition, when the target gear is changed, the virtual vehicle speed SpdVir of the virtual target gear TarGe and the virtual gear ratio rGi may be used to obtain the target input speed omega tar based on the virtual target gear. Then, during the gear shift, the virtual engine speed omega vir may be obtained by applying a preset speed limit to the target input speed based on the virtual current gear.

In the present invention, the current virtual engine speed omega vir during shifting may be obtained in real time from the real-time virtual vehicle speed, but may be determined as a value that changes from a virtual speed based on the current gear (i.e., a target input speed based on the virtual current gear) to a virtual speed based on the target gear (i.e., a target input speed based on the virtual target gear) while maintaining a preset rate limit (i.e., a change rate limit value).

Further, as the gear shift progresses to some extent, the virtual engine rotational speed omega vir set to the target input speed based on the virtual current gear (i.e., the virtual engine rotational speed of the virtual current gear) omega cur may be replaced with the target input speed based on the virtual target gear (i.e., the virtual engine rotational speed of the virtual target gear) omega tar. As an alternative method, the virtual engine speed omega vir may be obtained by multiplying the virtual gear ratio rGi corresponding to the previously calculated delay target gear by the virtual vehicle speed SpdVir as the reference vehicle speed and taking the speed limit value thereof.

Meanwhile, in the virtual shift model M of the virtual shift controller 22, the virtual current gear CurGe essentially represents the current gear at the previous time step (i.e., the current gear before the start of the shift) until the current shift completion condition is satisfied. In other words, the current gear value may be maintained until the shift completion condition is satisfied, and the virtual target gear determined by the shift schedule map may be maintained as the target gear after the shift is performed from the state before the shift is completed.

However, when the shift completion condition is satisfied after the shift start, the previous virtual target gear TarGe is satisfied is updated to the virtual current gear CurGe, and the previous target gear is made the current gear from the time point when the shift completion condition is satisfied. At this time, the shift completion condition may include one or more of the following conditions.

1) Condition for a virtual gear shift schedule xProgress value of 100%

2) Condition for resetting virtual gear shift schedule xProgress value to 0%

3) Condition that the virtual gear shift schedule value xprogrress is greater than a certain value

4) A condition that a difference between the virtual engine rotational speed omega vir and the virtual engine rotational speed omega for the virtual target gear (i.e., the target input speed based on the virtual target gear) omega tar is less than a certain value

5) A value obtained by multiplying the virtual gear ratio rGi corresponding to the retard target gear by the virtual vehicle speed SpdVir that is the reference vehicle speed is equal to a condition of the virtual engine speed omega vir obtained by taking the speed limit value for the multiplied value, or a condition of a difference between both values being equal to a certain value or less than or equal to a certain value.

When the "condition that the virtual shift schedule xProgress value is reset to 0% is described, in the case where the control logic is programmed to reach a state of 100% based on the virtual shift schedule, and is reset to 0% immediately after the state, it is possible to determine the time point of resetting to 0% as described above as the time point of completion of the shift. The shift schedule is maintained at 0% until the shift event is started again, but a point in time when the shift schedule first reaches 0% may be determined as the time when the shift is completed.

As described above, completion of the shift may be determined based on the virtual shift schedule xprogrress, but may also be determined based on the virtual engine speed. It is determined that the shift completion condition is satisfied even if the virtual engine speed converges such that the difference is less than or equal to the virtual engine speed of the virtual target gear.

Next, in a vehicle having a real transmission, since the gear ratio is reduced as an upshift occurs, the torque multiplication effect between the front and rear of the transmission is reduced, and finally, even if the engine generates the same torque, the final acceleration is reduced. To mimic this effect, the present invention may calculate a limit torque tqLmt for each virtual gear and limit the torque command with the limit torque. At this time, in the virtual shift model of the virtual shift controller 22, the limit torque tqLmt (which is the limit torque of the current gear) of each virtual gear can be calculated by multiplying all of the virtual gear ratio rGi, the virtual final gear ratio rFg, and the limit torque setting parameter corresponding to the virtual current gear CurGe.

In addition, it is possible to binarize in the driving direction and the regeneration direction of the motor and set the limit torque tqLmt of each virtual gear, which can be achieved by binarizing the limit torque setting parameter. In order to adjust the motor torque by applying the limit torque, it is possible to define the motor torque in the driving direction as a limit torque tqLmt value in the driving direction and define the motor torque in the regenerating direction as a limit torque tqLmt value in the regenerating direction.

In still another method, after a basic torque command is calculated by generating and adding three types of motor torque commands (regeneration, coasting, and driving), the torque command may be defined as a limit torque tqLmt value in the driving direction at the time of driving, and the torque command may be defined as a limit torque tqLmt value in the regeneration direction during coasting and regeneration (during which the vehicle travels in the coasting mode). Needless to say, the regenerative torque command and the coasting torque command may be 0 at the time of driving, and the driving torque command may be 0 at the time of regeneration or coasting.

In order to simulate the effect of the gear ratio for each gear to be applied proportionally and the maximum value of the limit torque, the ratio of the accelerator pedal input value (APS value) to the value of the limit torque tqLmt for the current driving direction may be used instead of the ratio of the accelerator pedal input value (APS value) to the maximum motor torque when determining the value between the accelerator pedal input value (APS value) and the driving torque.

In addition to the method of determining the torque command by the ratio of the simple accelerator pedal input value (APS value) to the limit torque tqLmt of each virtual gear, the torque command may be determined by the following torque ratio: the torque ratio is a function of a preset accelerator pedal input value for the limiting torque tqLmt. For example, the base torque command may be determined as a torque of 20%, 50%, and 80% of the limit torque tqLmt when the accelerator pedal input value is 20%, 50%, and 80%, respectively, but may be determined as a torque of 40%, 70%, and 85% of the limit torque tqLmt when the APS value is 20%, 50%, and 80%, and the torque ratio mapped to each APS value is 40%, 70%, and 85%, respectively.

Fig. 6 is a graph showing the maximum motor torque curve of the present invention depending on the motor rotation speed and the limit torque of each virtual gear (1 st, 2 nd, 3 rd, 4 th, 5 th gears … …). Referring to fig. 6, it can be seen that the greater the motor speed, the greater the number of gears (i.e., the number of gears), and the greater the number of gears (i.e., the higher the gear), the smaller the maximum motor torque.

In addition, in the high gear, as the number of gears increases, the gear ratio decreases, and eventually the wheel transmission torque decreases, as compared with the low gear. The maximum motor torque curve is a curve representing a maximum allowable torque preset for each motor rotation speed, and the limit torque of each virtual gear can be calculated by applying gear ratio information of each gear.

Fig. 6 shows various examples in which the limit torque of each virtual gear is determined, and the limit torque of each virtual gear (i.e., the limit torque of the current gear) can be calculated by multiplying all of the virtual gear ratio rGi corresponding to the virtual current gear CurGe, the virtual final gear ratio rFg, and the limit torque setting parameter, as described above.

Therefore, the magnitude of the limit torque of each virtual gear can be set according to the value of the limit torque setting parameter, and referring to fig. 6, it is shown that the limit torque of each virtual gear can be adjusted to a value higher or lower than the maximum motor torque curve. For example, the limit torque of each virtual gear may be set to a value larger than the maximum motor torque curve to include all of the values thereof, as shown in fig. 6, and in this case, the maximum performance of the motor may be utilized.

Alternatively, the profile of the limit torque of each virtual gear may be set in a form intersecting with the maximum motor torque profile, wherein in some regions of the motor rotation speed of each virtual gear, the limit torque of that gear is set to a value higher than the maximum motor torque profile, and in the remaining regions, the limit torque may be set to a value lower than or equal to the maximum motor torque profile. Thus, the maximum performance of the electric machine can be utilized in certain regions of the motor speed of each virtual gear, and the effect of the gear ratio difference between the gears can also be achieved in certain regions.

In addition, the limit torque of each virtual gear may be set to a value smaller than the maximum motor torque curve throughout the entire range of motor speeds, and in this case, the maximum performance of the motor may not be utilized, but the effect of the gear ratio difference between the gears may be maximized. Meanwhile, the final torque command generator 23 of the first controller 20 may be configured to receive the aggregated base torque command from the torque command generator 21 and the virtual shift intervention torque command from the virtual shift controller 22.

The final torque command generator 23 may then be configured to correct the base torque command generated by the torque command generator 21 with the virtual shift intervention torque command generated by the virtual shift controller 22, and at this time, in addition to the summed base torque command, a virtual shift intervention torque command (which is a correction torque command for generating a virtual shift feel) may be further added to generate a final torque command.

FIG. 7 is a graph illustrating an example of a virtual shift intervention torque curve of the present invention. Accordingly, the second controller 30 may be configured to receive the final torque command generated and output by the final torque command generator 23 of the first controller 20 and then operate the inverter to operate the driving motor 41 according to the received final torque command. Therefore, a vehicle judder (jerk) phenomenon occurring due to the shift effect similar to the shift effect at the time of the real transmission shift can be achieved during the virtual shift.

In the virtual shift model of the virtual shift controller 22, the virtual shift intervention torque tqItv may be provided in the form of a torque curve using the virtual shift schedule xprogess as an independent variable. Alternatively, the virtual shift intervention torque tqItv may be provided by a model based on physical values reflecting: the virtual engine speed omega vir information, the target input speed based on the virtual current gear (i.e., the virtual engine speed of the virtual current gear) omega vir, and the target input speed based on the virtual target gear (i.e., the virtual engine speed of the virtual target gear) omega tar.

In addition, in calculating the virtual shift intervention torque command, the form of the virtual shift intervention torque should be changed according to the type of transmission and the shift category, and the types of transmissions may be classified into an Automatic Transmission (AT), a Dual Clutch Transmission (DCT), and an Automatic Manual Transmission (AMT). The gear shifting types can be divided into power-on gear-up, power-off gear-up (pedal return-foot-up), power-on gear-down (kick-down), power-off gear-down, near-stop gear-down and the like.

To calculate the virtual shift intervention torque command, a current shift category may be determined by the virtual shift controller 22, and in the determination method, the current shift category is an upshift when the virtual target gear TarGe is higher than the virtual current gear CurGe (i.e., virtual target gear > virtual current gear), and the current shift category is a downshift when the virtual target gear is lower than the virtual current gear (i.e., virtual target gear < virtual current gear). Further, when the basic torque command is larger than the preset reference torque value, it is in the power-on state, and when the basic torque command is smaller than the preset reference torque value, it is in the power-off state.

Finally, in the present invention, when the current shift category is determined based on the virtual current gear, the virtual target gear, and the like, among the virtual shift intervention torque curves of each shift category, the virtual shift intervention torque curve corresponding to the current shift category may be selected, and the virtual shift intervention torque for generating the virtual shift feel may be determined in real time from the selected virtual shift intervention torque curve.

At this time, a virtual shift intervention torque value corresponding to the current virtual shift schedule may be determined from the selected virtual shift intervention torque curve. The virtual shift intervention torque curve is information that is preset for each shift category in the virtual shift model M of the virtual shift controller 22. In addition to the shift categories, differential virtual shift intervention torque curves can be preset according to the gear types. The magnitude of the virtual shift intervention torque may be adjusted by using as the torque magnitude setting variable: at least one or more of a virtual engine speed omega vir, an accelerator pedal input value (APS value), an actual motor torque (i.e., a motor base torque command generated by a torque command generator), and one or a combination of both of a virtual current gear currge and a virtual target gear TarGe.

Generally, as the magnitude of the motor torque (i.e., the base torque command) increases, the magnitude of the virtual shift intervention torque increases; as the gears become higher, the magnitude of the virtual shift intervention torque decreases due to the gear ratio between the gears; and as the virtual engine speed increases, the degree of decrease and the degree of increase in the speed at the time of shifting increase, so the magnitude of the virtual shift intervention torque naturally increases.

Further, even if the actual motor rotation speed omega m is low, the virtual engine rotation speed omega vir is high. At this time, in order to simulate the behavior of the transmission-equipped vehicle, the virtual red region may be determined when the virtual engine speed omega vir is greater than or equal to a preset threshold speed value. In particular, the threshold rotation speed refers to a maximum allowable rotation speed (rpm) of the engine, which is predetermined in the conventional internal combustion engine vehicle, and it may be determined that the red region has been entered when the virtual engine rotation speed exceeds the threshold rotation speed (see step S15 of fig. 3).

In the automatic shift mode, the shift schedule may be preset so that an upshift is performed before entering the red region, so that it is not necessary to determine the virtual red region, but when entering the manual shift mode, the virtual gear is maintained until the driver's intention is input, so that the virtual red region can be entered. In response to determining that the virtual red region is entered, a fuel cut condition of the engine may be simulated by performing virtual fuel cut control, and the simulation may be performed by generating a motor torque command targeting a threshold rotation speed at which the virtual red region starts, thereby controlling the motor (see step S15 of fig. 3).

For example, a proportional torque reduction control or a PID torque control may be performed using the error between the current virtual engine speed omega vir and the threshold speed. In another approach, the torque command may be set to a predetermined value to decelerate when a threshold rotational speed is exceeded, and the driver desired torque may be restored when the rotational speed is reduced to less than the threshold rotational speed. Further, in response to determining that the virtual red region has been entered to simulate a fuel cut condition, the considered torque ripple may additionally be added to the base torque command.

At this time, a torque fluctuation having a predetermined magnitude and period may be added to the basic torque command at the time of fuel cut, thereby enabling vibration in the case of virtual fuel cut. In addition, in all cases, when the basic torque command according to the driver's intention is smaller than the torque command of the control target that sets the threshold rotation speed at the start of the virtual red region as the virtual engine rotation speed, the red region control torque may be ignored, and only the basic torque command according to the driver's intention is applied. In this way, the control method for generating the virtual gear change feeling of the electric vehicle according to the present invention has been described. Fig. 8 is a diagram showing a shift state and a vehicle behavior state during virtual shifting according to the present invention.

Referring to fig. 8, when the virtual vehicle speed is obtained from the actual motor speed omega detected by the motor speed detector, the virtual target gear may be determined from the accelerator pedal input information and the virtual vehicle speed, and the gear shift simulating the virtual target gear may be performed. Furthermore, the same acceleration state representing the behavior of the vehicle as the actual gear shift can be detected at each virtual gear shift.

Meanwhile, in the present invention, when the virtual shift function is implemented in the electric vehicle, driver set variables involved in generating the virtual shift are defined, and in order to generate a virtual shift feel while driving, variable values preset by the driver (i.e., the above-described driver set information) may be reflected, so that it is possible to provide an individualized and differentiated virtual shift feel to each driver.

The driver set variable may be the same as or different from the virtual shift intermediate variable described above. For example, in the virtual shift intermediate variables shown in fig. 2, the virtual final gear ratio rFg may be one piece of driver setting information that the driver has previously input and set, and the remaining virtual shift intermediate variables other than the virtual final gear ratio are variables obtained from input variables, which are predetermined vehicle driving information, for generating a virtual shift feel in the virtual shift model.

The driver setting information is information that a driver can set, change, and adjust through a device connected to the vehicle (for example, a mobile device capable of communicating with the first controller 20 or the interface portion 11 connected to the first controller 20) for generating a desired virtual shift feel to personalize the virtual shift feel. In the present invention, the driver setting information may be input and set in the virtual shift controller 22 of the first controller 20, and used to generate a virtual shift feel from the vehicle driving information in the virtual shift model M. In the present invention, even when the value of the input variable is the same as that in the virtual shift model M of the virtual shift controller 22, the value of the output variable (e.g., virtual shift intervention torque) can be changed in accordance with the driver setting information (i.e., the value of the driver setting variable).

The above-described virtual shift intermediate variable and driver set variable are variables for virtual shift control obtained or used in the virtual shift model M of the virtual shift controller 22, and the virtual shift intervention torque, which is the correction torque for generating the virtual shift feel, is a variable for calculating or generating the torque command. In the present invention, driver setting information (i.e., variables related to generating a virtual shift) provided to enable a driver to set and adjust a personalized virtual shift feel is as follows:

number of gears

Total Shift time (i.e., Shift speed)

Magnitude of virtual shift intervention torque

Form of virtual shift intervention torque

Virtual final gear ratio rFg

Hysteresis between upshifting and downshifting

-a shift schedule map

Limiting torque for each virtual gear

Virtual idle speed

Virtual idle vibration

-virtual engine speed scaling

Fuel cut-off threshold speed

Magnitude of torque fluctuation during fuel cut

Period of torque fluctuation during fuel cut

In the present invention, at least one or more pieces of the above-described driver setting information may be input and set to a controller (specifically, the virtual shift controller 22 of the first controller 20) in advance, and used to generate a virtual shift feel.

Fig. 9 is a flowchart showing a process of inputting and using driver setting information of the present invention. The method described below may be performed by a controller. As shown in fig. 9, the process of changing the driver setting information may include: step S1, step S2, steps S3 and S4, and step S5, at step S1, it is determined whether the driver inputs changed driver setting information through the interface part 11 or the mobile device to change the personalized setting of the virtual shift function; the driver setting information is changed to the input information when there is a setting change at step S2, the stored information is applied to the virtual shift function when the changed setting information is stored at steps S3 and S4, and the changed setting information is restored to the previously stored value when not stored at step S5.

Hereinafter, each driver set variable provided as settable and adjustable in the present invention will be described in more detail.

Number of gear positions

The driver can set the number of gears of the virtual transmission to be used. For example, one of the multi-speed transmissions, such as a 4-speed transmission to an 8-speed transmission, may be selected. The setting of the number of gears of the virtual transmission can be realized by: a virtual shift model and a shift schedule map are respectively prepared based on each transmission type, and then the virtual shift model M and the shift schedule map of the corresponding transmission are selected and applied when the driver selects the gear type and the number of gears desired by the driver.

Alternatively, after providing the virtual gear model with the maximum number of gears and the gear plan map selectable by the driver, this can also be implemented as follows: entry into a higher gear than the highest gear of the number of gears selected by the driver in the virtual shift model M and the shift plan map is prevented. For example, when the maximum gear that the driver can select is 8, after equipping the virtual shift model and the shift schedule map of an 8-gear virtual transmission, 7-gear and 8-gear can be prevented from being entered when the driver selects a 6-gear transmission.

In particular, since the number of gears is typically reduced, the virtual final gear ratio rFg should be reduced compared to when 8 gears are selected. At this time, the adjusted value of the virtual final gear ratio rFg may be reflected in the value of the virtual speed SpdVir (km/h), which is an input of the shift plan map, so that the entire virtual shift function may be implemented. The virtual vehicle speed SpdVir may be calculated as a value proportional to a value obtained by multiplying the actual motor rotation speed omega m measured by the motor rotation speed detector by the virtual gear ratio rFg.

Total Shift time (Shift speed)

The driver can set and adjust the total shift time required to make the shift. The gear shifting process has a torque phase in which the torque magnitude fluctuates and an inertia phase (inertia phase) in which slippage and actual change of the virtual engine speed occur, and the total gear shifting time required when gear shifting is performed is the sum of the time for performing all the phases.

When adjusting the shift speed, a function of adjusting the time of the torque phase and the inertia phase separately may be provided. Alternatively, the total time required, i.e. the total shift time itself, may be adjusted. When setting and adjusting the required aggregate time as described above, the ratio between the time of the torque phase and the time of the inertia phase may be maintained at a preset value.

In addition, when the driver increases the set value of the required time, the rate of change of the virtual engine speed (i.e., the rate limit value) decreases. In other words, when a fast shift speed is desired, the required time is set to be short, and therefore, the rate of change in the virtual engine speed increases (i.e., the engine speed increases sharply), whereas when a slow shift speed is desired, the required time is set to be long, and therefore, the rate of change in the virtual engine speed decreases (i.e., the engine speed increases gradually).

Magnitude of virtual shift intervention torque

The driver may be allowed to set the magnitude of the intervening torque at the time of the shift, i.e., the magnitude of the virtual shift intervening torque. In particular, the virtual shift intervention torque refers to a torque that intervenes only for generating a virtual shift feel, not a torque for driving the vehicle. In other words, as described above, the virtual shift intervention torque is a correction torque added to the base torque command for generating a virtual shift feel.

When determining the magnitude of the virtual shift intervention torque, a batch personalization method may be applied, wherein the relative magnitude of the virtual shift intervention torque for each case may be preset and may be set to be larger or smaller based on the ratio. In particular, only one set value controlling the magnitude of the virtual shift intervention torque is changed.

In addition, a function of changing the magnitude of the shift intervention torque for each case without being changed in a batch adjustment manner may be provided. In particular, a torque magnitude map utilizing a combination of accelerator pedal input value (APS value), virtual engine speed, and virtual target gear (or virtual current gear), or one or more variables selected therefrom, may be selected or adjusted along with the magnitude of the virtual shift intervention torque.

Alternatively, the torque magnitude map may be selected or adjusted for each known shift category (e.g., power-on upshift, power-off upshift (lift-foot-up), power-on downshift (kick-down), power-off downshift, near-stop downshift, etc.), and any combination of the above may also be adjusted with a compound input.

Form of virtual shift intervention torque

The driver may be allowed to select or set a form of torque to intervene in shifting (i.e., virtual shift intervention torque). In fact, in a vehicle equipped with a transmission, there is a difference in shift feel based on the type of transmission. To simulate this phenomenon, the driver may select the type of virtual transmission to determine a form of virtual shift intervention torque for simulating a shift feel of the respective transmission. In the present invention, setting the magnitude and form of the virtual shift intervention torque is meant to include selecting the type of transmission.

For example, among transmission types such as an Automatic Transmission (AT), a Dual Clutch Transmission (DCT), and an Automatic Manual Transmission (AMT), a desired type of virtual shift intervention torque may be selected. In addition, the present invention may further guide the driver in enabling visualization of the form of torque.

Fig. 7, 10, and 11 are graphs showing examples of virtual shift feel depending on the virtual transmission type of the present invention, with time on the horizontal axis and torque on the vertical axis. The form of the shift torque represents the form of the virtual shift intervention torque for each shift category based on the virtual transmission type, and examples thereof are shown in fig. 7, 10, and 11. Fig. 7 shows the energization upshift time of the DCT, fig. 10 shows the energization upshift time of the Automatic Manual Transmission (AMT), and fig. 11 shows the energization upshift time of the Automatic Transmission (AT).

Fig. 12 and 13 are diagrams illustrating a method of personalizing the form of the virtual shift intervention torque according to the virtual transmission type desired by the driver of the present invention, and illustrate an example of an energized upshift (i.e., shift category) of an automatic manual transmission (i.e., transmission type). Fig. 12 shows an example of detailed items that can be adjusted by the driver.

In the present invention, the driver-adjustable detailed items for setting the form of the shift torque may include: torque reduction amount a, torque reduction time B, torque recovery ratio C, thrust degree D, and torque oscillation E, the present invention allows the driver to adjust the values of these detailed items. Thus, a base curve of virtual shift intervention torque for each shift category may be provided by pre-inputting to the virtual shift controller 22 based on the virtual transmission type. The above detailed items are listed as the above a to E, and therefore, the driver can adjust each detailed item in the basic curve. In other words, the form of the virtual shift intervention torque may be set by re-inputting or adjusting the value of each detailed item displayed on the interface portion 11 or the screen of the mobile device.

As another method, as shown in fig. 13, after a plurality of feature points for determining the form of the virtual shift intervention torque are displayed and provided on the display screen of the interface portion 11 or the mobile device, the present invention guides the driver to adjust the positions of the feature points within the allowable area (i.e., the shaded square area), thus allowing the driver to directly adjust the form of the virtual shift intervention torque.

Virtual final gear ratio rFg

The driver may change the virtual final gear ratio rFg and, at this time, adjust the virtual final gear ratio within its upper and lower limits. When the value of the virtual final drive ratio rFg is decreased, a long gear is set, and when the value of the virtual final drive ratio is increased, a short gear is set.

Fig. 14 shows an example of a long range setting of the virtual final gear ratio rFg, and fig. 15 shows an example of a short range setting thereof, in which each shift schedule map, the virtual engine speed, the maximum motor torque curve depending on the motor speed, and the limit torque tqLmt of each virtual gear are shown.

In the case of the long gear setting as shown in fig. 14, it is necessary to simulate a sparse shift due to the effect of the increase in the ratio between gears (ratios), and in the case of the short gear setting as shown in fig. 15, it is necessary to simulate a tight shift. When the virtual vehicle speed is obtained as an input of the shift schedule map, the simulation may be implemented with a value multiplied by the virtual final gear ratio rFg.

In addition, in order to simulate the difference in magnitude of output torque due to gear ratio change, when the limit torque tqLmt of each virtual gear described later is a short gear setting, it should be increased in proportion to the increased virtual final gear ratio rFg, and when set for a long gear, it should be decreased in proportion to the decreased virtual final gear ratio rFg. When calculating the limit torque tqLmt of each virtual gear, the simulation may be implemented by multiplying the virtual gear ratio rGi corresponding to the virtual current gear CurGe and the limit torque setting parameter by the virtual final gear ratio rFg to obtain values.

Shift plan map

The shift schedule map allows the driver to select a shift schedule map (i.e., a shift map). When selecting a shift schedule map, a function of adjusting the individual shift schedule curves of the shift schedule map may be provided, but since there are many complicated components when providing the entire function, it is preferable to provide a limited adjustment function. One method is to select one of several preset shift schedule maps: comfort mode, normal mode and sport mode.

Fig. 16 to 18 are diagrams showing predetermined shift schedule maps selectable by the driver of the present invention. Fig. 16 shows the shift schedule map in the normal mode, fig. 17 shows the shift schedule map in the comfort mode, and fig. 18 shows the shift schedule map in the sport mode. As shown in the figure, the horizontal axis of the shift schedule map represents the virtual vehicle speed (km/h), and the vertical axis of the shift schedule map may represent the accelerator pedal input value (APS value) (%) or the acceleration load.

The shift schedule map in the comfort mode is a shift schedule map set to use a high gear (high gear) at a low speed as much as possible, so as to guide to keep the virtual engine speed omega vir as low as possible. In contrast, the shift schedule map in the sport mode uses a low gear (low gear) as much as possible, so that the virtual engine speed is kept as high as possible, thereby guiding responsiveness and using maximum torque while driving in the sport mode. The reason why the shift schedule map of the sport mode can guide the use of the maximum torque even with the virtual shift function is that the limit torque of each virtual gear is applied as described below.

Hysteresis between lifting shifts

The change in hysteresis between the upshifting and downshifting shifts may be generated by adjusting a shift schedule map for an upshift and a shift schedule map for a downshift (i.e., shift schedule curves), or may be implemented by fixing input shafts (i.e., values of the vertical and horizontal axes of the maps) used in the shift schedule map and the offset shift schedule map.

Fig. 19 is a diagram showing an example of hysteresis setting of the shift schedule map of the invention, fig. 19 shows an example of low hysteresis, and fig. 20 shows an example of high hysteresis. The solid lines in each figure represent upshift schedule curves, and the dashed lines in each figure represent downshift schedule curves. In addition, in the shift schedule map, the horizontal axis represents the virtual vehicle speed (km/h), and in the shift schedule map, the vertical axis represents the accelerator pedal input value (APS value) (%) or the acceleration load.

As shown in fig. 19, a busy shift may occur when a low hysteresis is applied with a relatively small hysteresis offset value, and as shown in fig. 20, a sparse shift may occur when a high hysteresis is applied with a relatively large hysteresis offset value.

The reduced hysteresis (i.e., low hysteresis in fig. 19) allows for immediate shifting depending on speed or load, thereby improving vehicle acceleration/deceleration responsiveness, enabling the driver to experience busy shifts, and adapting to sporty mode as the shift frequency increases. Conversely, an increase in hysteresis (i.e., a high hysteresis in fig. 20) can prevent busy shifts due to slight fluctuations in vehicle speed or load, and is suitable for a comfort mode because a sparse shift is achieved by reducing the shift frequency.

Since adjusting the hysteresis by adjusting the values of the shift schedule map may be complicated and may cause many objects to be adjusted, the virtual vehicle speed binarization method may be applied as one of the shift methods of the input shaft. In other words, when upshifting, the virtual vehicle speed (which becomes the virtual vehicle speed for upshifting) is directly used in the shift schedule map, and when downshifting, a separate virtual vehicle speed for downshifting is used in the shift schedule map. At this time, the virtual vehicle speed for the downshift may be calculated by applying a preset scale factor and a compensation value to the virtual vehicle speed (i.e., the virtual vehicle speed for the upshift). Specifically, the virtual vehicle speed for the downshift may be obtained by multiplying the virtual vehicle speed (i.e., the virtual vehicle speed for the upshift) by a scaling factor greater than 1 and adding the positive compensation value. In particular, the hysteresis between gears can be given when using a single map.

In the above, it has been described that the offset is made by binarizing the virtual vehicle speed, which is the horizontal axis value among variables used as inputs to the shift schedule map (i.e., the shift map), but the offset may be made by binarizing the accelerator pedal input value (APS value) or the acceleration load value (i.e., the vertical axis value) in the same manner, instead of the virtual vehicle speed. Alternatively, the shifting may be performed by binarizing both the vertical axis value and the horizontal axis value, which are the two input variable values of the shift schedule map.

Alternatively, shift schedule maps for upshift and downshift may be provided for use, respectively, and in this case, it is no problem to use only the virtual vehicle speed as the reference speed.

Limiting torque of each virtual gear

Next, in a vehicle having a real transmission, when an upshift is performed, the torque multiplication effect between the front and rear of the transmission is reduced due to a reduction in the gear ratio. Finally, even when the engine generates the same torque, the final acceleration is reduced. To simulate this effect, the present invention applies the limit torque tqLmt of each virtual gear in the virtual shift function, and can limit the torque command in the corresponding virtual gear with the limit torque of each virtual gear.

However, the limits of each gear need to be specified to reliably produce this effect. Since the value of the limit torque of each virtual gear should be applied within the range of the maximum torque curve and the maximum equal power curve of the motor, there is a limit that the maximum performance of the motor cannot be utilized. The invention thus provides a function that enables the part to be adapted to the driver's choice.

In other words, in order to experience the effect of changing the gear ratio by the virtual shift function in all cases, the limit torque of each virtual gear may be set to be below the motor maximum torque curve. All values of the limit torque of each virtual gear may be set to values smaller than the value of the maximum motor torque curve. Instead, in order to utilize the maximum performance of the electric machine in all cases, the limit torque of each virtual gear may be set to lie above the maximum electric machine torque curve. All values of the limit torque of each virtual gear may be set to values larger than the value of the maximum motor torque curve.

Alternatively, adjustment may be made between the above two methods, and the curve of the limit torque of each virtual gear may be set in a form intersecting the curve of the maximum motor torque. In some regions of the motor rotation speed of each virtual gear, the limit torque of the corresponding gear may be set to be greater than the maximum motor torque curve, and in the remaining regions, the limit torque may be set to a value less than or equal to the maximum motor torque curve. Thus, the maximum performance of the electric machine can be utilized in certain regions of the motor speed of each virtual gear, and the effect of the inter-gear transmission ratio differences can also be achieved in certain regions.

In the present invention, since the limit torque tqLmt of each virtual gear, which is the limit torque of the current gear, can be calculated by multiplying all of the virtual gear ratio rGi, the virtual final gear ratio rFg, and the limit torque setting parameter corresponding to the virtual current gear CurGe, with respect to the limit torque of each virtual gear as the driver setting information, the limit torque value of each virtual gear may itself be the driver setting information, may be set and adjusted by the driver, and the limit torque setting parameter together with the virtual final gear ratio rFg may be the driver setting information.

Virtual idle speed

The virtual idle speed allows the driver to adjust and set the engine speed (rpm) during the virtual idle. In an electric vehicle, the motor speed (rpm) is zero when the vehicle is parked. However, when the engine is turned on, the actual engine maintains a rotational speed greater than the idle speed. To achieve this effect, a virtual idle speed (which serves as a lower limit value of the virtual engine speed) may be set to display the virtual idle speed in the cluster panel, or a virtual engine sound may be output together with the virtual idle speed when idling. In the present invention, the virtual idle speed may be adjusted by the driver in the in-vehicle interface section 11 or the mobile device.

In addition, the following functions may be additionally applied: the driver is allowed to adjust the individual virtual idle speed when the accelerator pedal is depressed with the brake pedal depressed at the stop or when the driver wants to start the launch by other input.

Virtual idle vibration

At the time of virtual idling, the actual motor 41 is stopped, but a vibration torque may be additionally applied to the motor, thereby imparting an idling feeling to the driver. Thus, in the present invention, a function can be provided that: the driver is allowed to set the magnitude and period of the vibration torque by using the interface portion 11 or the mobile device in the vehicle to thereby achieve personalization.

At the time of virtual idling, the first controller 20 may be configured to generate and output a vibration torque command according to the magnitude and period set by the driver, and the second controller 30 may be configured to respond to the vibration torque command input from the first controller 20, and thus the driving of the motor 41 may be controlled accordingly.

Virtual engine speed scaling

In the present invention, the virtual engine speed determined by the virtual shift controller 22 may be displayed on the cluster panel. At this time, the virtual engine speed may be displayed in the cluster panel for the sake of sensitivity, and does not need to reflect the physical value of the actual motor. Therefore, in the present invention, the driver can be allowed to adjust the scale (scale) of the virtual engine speed.

As an exemplary embodiment, a percentage may be used in the cluster panel to display a virtual engine speed between 0 and 100%. In addition, the virtual engine speed may be displayed as a value within a virtual value range having the actual motor limit speed as the highest value. In addition, in a typical internal combustion engine vehicle, the virtual engine speed may be displayed on a scale of about 0 to 6500rpm (which is a range of engine speeds). In addition, a function may be provided that is capable of selecting one of the predetermined custom scales.

Fuel cut-off threshold speed

The driver can specify the fuel cut threshold rotation speed as the upper limit value of the virtual engine rotation speed, i.e., the threshold rotation speed at which the virtual fuel cut starts. The fuel cut threshold rotation speed is specified based on a value within a range selected from the above-described virtual engine rotation speed scale. For example, when the driver selects the percentage representation as the instrument cluster representation of the virtual engine speed, a speed corresponding to about 95% of the virtual engine speed may be specified and used as the fuel cut threshold speed.

Magnitude and period of torque ripple during fuel cut

When the virtual fuel cut function is activated, the torque command desired by the driver is not applied, but a torque command not exceeding the fuel cut threshold rotation speed is applied. At this time, the vibration torque may be added to simulate the feel of the internal combustion engine vehicle, thereby allowing the driver to adjust the magnitude and period of the vibration torque fluctuation. In particular, when the cycle frequency is 2Hz or less, analog emotion can be simulated and added, and when the cycle frequency is 2Hz or more, digital emotion or future emotion can be simulated and added.

Although exemplary embodiments of the present invention have been described above in detail, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic idea of the present invention defined in the claims also fall within the scope of the present invention.