Control device and method for electric vehicle realizing virtual driving system experience

Abstract

A control device and method for an electric vehicle for realizing a virtual driving system feeling are disclosed. The main purpose is to provide a control device and method for an electric vehicle, which can realize and provide a driving feeling that can be felt differently in other driving systems (such as the driving system of an internal combustion engine vehicle). The control method includes: determining, by a controller, a basic torque command for controlling the operation of a drive motor from vehicle driving information collected while driving the vehicle; determining a virtual driving system torque command from the determined basic torque command by using a virtual driving system model preset in the controller, the virtual driving system torque command being a correction torque command for realizing the virtual driving system feeling; and controlling, by the controller, the torque of the drive motor according to the determined virtual driving system torque command.

Description

Technical Field

[0001] The present invention relates to a control device and method for an electric vehicle, and more particularly, to a control device and method capable of generating a differentiated virtual driving experience that can be felt in other driving systems (such as a driving system of an internal combustion engine vehicle) to provide a driving experience to a driver in the electric vehicle. Background Art

[0002] As is well known, an electric vehicle (EV) is a vehicle that is driven using a motor as a driving power source of the vehicle.

[0003] The driving system of an electric vehicle includes: a battery that provides power for driving a motor; an inverter that is connected to the battery and drives and controls the motor; a motor that is connected to the battery through the inverter to enable charging and discharging; and a reducer that reduces the rotational force of the motor and transmits the rotational force to the drive wheels.

[0004] Here, when driving the motor, the inverter converts direct current (DC) supplied from the battery into alternating current (AC) to be applied to the motor through a power cable, and when using motor regenerative energy, the inverter converts alternating current (AC) generated by the motor operating as a generator into direct current (DC) to be supplied to the battery, thereby charging the battery.

[0005] Unlike conventional internal combustion engine vehicles, ordinary electric vehicles do not use a multi-speed transmission, but instead a speed reducer with a fixed gear ratio is set between the motor and the drive wheels.

[0006] The reason is that, unlike an internal combustion engine which has a wide distribution range of energy efficiency depending on the operating point and can only provide high torque in the high-speed area, in the case of a motor, the efficiency difference is relatively small relative to the operating point, and low-speed high torque can be achieved only by the individual characteristics of the motor.

[0007] Due to the characteristics of the electric vehicle driving system, the natural vibration characteristics generated by the torsional vibration damper, the dual mass flywheel, etc. used in the driving system of the internal combustion engine vehicle cannot occur in the electric vehicle.

[0008] The absence of vibrations while driving the vehicle can provide an obvious advantage in providing seamless and smooth drivability, but depending on the driver's inclinations or the sporty inclinations of the vehicle, it is also desirable to provide the driver with the feeling of vibrations added for driving pleasure. Summary of the invention

[0009] Therefore, embodiments of the present invention are designed to solve the above-mentioned problems, and an object of the present invention is to provide a control device and method for an electric vehicle, in which the control device and method can virtually implement and simulate various characteristics that can be provided by other driving systems (such as the driving system of an internal combustion engine vehicle) according to the driver's requirements by using a motor in the electric vehicle, and enable the driver to experience the driving feeling that can be felt in other driving systems in the electric vehicle.

[0010] The objects of the present disclosure are not limited to the above objects, and those skilled in the art (hereinafter referred to as "ordinary technicians") will clearly understand other objects not mentioned herein from the following description.

[0011] In order to achieve the above-mentioned purpose, according to one aspect of an embodiment of the present disclosure, a control method for an electric vehicle that realizes a virtual driving system feeling is provided, the control method comprising: determining, by a controller, a basic torque command for controlling the operation of a drive motor from vehicle driving information collected while driving the vehicle; determining a virtual driving system torque command from the determined basic torque command by using a virtual driving system model preset in the controller, the virtual driving system torque command being a correction torque command for realizing the virtual driving system feeling; and controlling, by the controller, the torque of the drive motor according to the determined virtual driving system torque command.

[0012] Here, the control method of the electric vehicle according to the embodiment of the present invention may further include changing a driver setting variable value determined in a virtual driving system model for determining a virtual driving system torque command from a basic torque command according to a change input of a driver in the controller.

[0013] In addition, according to another aspect of an embodiment of the present disclosure, a control device for an electric vehicle is provided, the control device including: a first controller, which generates and outputs a virtual driving system torque command; and a second controller, which controls the torque of a drive motor according to the virtual driving system torque command output from the first controller, wherein the first controller may include: a basic torque command generating unit, which is used to determine a basic torque command for controlling the operation of the drive motor based on vehicle driving information collected during driving the vehicle; and a virtual driving system mode control unit, which is used to determine a virtual driving system torque command from the basic torque command determined by the basic torque command generating unit by using a set virtual driving system model in a state where the virtual driving system model has been preset, and the virtual driving system torque command is a correction torque command for realizing a virtual driving system feel.

[0014] Here, the control device of the electric vehicle according to the embodiment of the present disclosure may further include an interface portion configured to allow a driver to input changes to driver setting variable values ​​determined in a virtual driving system model set in the virtual driving system mode control portion.

[0015] Therefore, according to the control device and method of the electric vehicle according to the embodiment of the present invention, by using the motor in the electric vehicle according to the driver's requirements, various features that can be provided by other driving systems (such as the driving system of an internal combustion engine vehicle) can be virtually implemented and simulated.

[0016] Therefore, the driver can experience the driving feeling that can be felt in other driving systems in his / her vehicle, and thus the marketability of the electric vehicle can be enhanced.

[0017] Furthermore, the driver can directly and freely change and adjust variables related to the generation and realization of the virtual driving system feeling, so that the driver can be provided with his / her own favorite virtual driving system feeling.

[0018] Therefore, a virtual driving system feeling generated by the variable values ​​changed and adjusted by the driver himself can be provided to the driver, thereby being able to personalize and differentiate the virtual driving system feeling in the electric vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a block diagram illustrating a configuration of an apparatus for controlling an electric vehicle according to an embodiment of the present disclosure.

[0020] Figure 2 : is a block diagram showing a state in which a torque command corrected by using a virtual driving system model is generated from a basic torque command in an embodiment of the present disclosure.

[0021] Figure 3 is a flowchart illustrating a process of executing a virtual driving system mode in an embodiment of the present disclosure.

[0022] Figure 4 , Figure 5 ,as well as Figure 6 is a view illustrating an example of personalization and correction of a torque command in achieving a virtual driving system feel according to an embodiment of the present disclosure.

[0023] Figure 7 is a block diagram illustrating an example of a method of adjusting amplitude in an embodiment of the present disclosure.

[0024] Figure 8 : is a diagram showing examples of various torque forms depending on the setting values ​​of the natural vibration frequency and the damping ratio in the embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] Only for the purpose of describing the embodiments according to the concepts of the present disclosure, the specific structures and functional descriptions presented in the embodiments of the present disclosure are illustrated, and the embodiments according to the concepts of the present disclosure can be implemented in various forms. In addition, it should not be interpreted as being limited to the embodiments described herein, and should be understood to include all modifications, equivalents, and substitutes included in the ideas and scope of the embodiments of the present disclosure.

[0026] Meanwhile, in the embodiments of the present disclosure, it will be understood that although the terms "first", "second", etc. are used herein to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from other components. For example, within the scope of the rights of the concepts of the embodiments of the present disclosure, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

[0027] It should be understood that when a component is referred to as being "coupled" or "connected" to another component, the component may be directly coupled or connected to the other component, or an intermediate component may exist between the component and the other component. Conversely, when a component is described as being "directly connected," "directly coupled," or "directly linked" to another component, it should be understood that there are no intermediate components between the component and the other component. Other expressions used to explain the relationship between components (such as "between," "directly between," "adjacent," or "directly adjacent") should also be interpreted in the same manner.

[0028] Throughout the specification, the same reference numerals represent the same components. The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present disclosure. In this specification, unless otherwise specified, the singular form also includes the plural form. In the "include" and / or "comprising" used in the specification, the parts, steps, actions and / or elements mentioned do not exclude the existence or addition of one or more other parts, steps, actions and / or elements.

[0029] Embodiments of the present disclosure relate to a control device and method for an electric vehicle that implements a virtual driving system experience, and more particularly, to a control device and method for an electric vehicle that can implement and provide a distinguishable virtual driving experience that can be felt in other driving systems.

[0030] More specifically, an embodiment of the present disclosure provides a control device and method, in which various features that can be provided by other driving systems (such as the driving system of an internal combustion engine vehicle) can be virtually implemented and simulated by using a drive motor in an electric vehicle according to the driver's requirements, so as to enable the driver to virtually experience the driving feeling of other driving systems.

[0031] When torque that can be virtually implemented and simulated to simulate the characteristics of various driving systems is generated according to the driver's request in an electric vehicle, a function can be achieved that allows the driver to virtually experience various driving sensations in his or her vehicle without having to change vehicles, thereby providing differentiation and marketability improvements for electric vehicles.

[0032] In addition, when the driving feel of other driving systems is differentiated according to personal preferences and virtually provided to drivers who value the driving feel in electric vehicles, not only is the more differentiated fun factor of electric vehicles highlighted, but also the personalization of the driving system can be achieved, wherein the feel of the virtual driving system is differentiated according to the driver.

[0033] In conventional internal combustion engine vehicles, there are limitations in achieving personalization in which the vehicle's driving system feel is differentiated for each driver due to reasons such as fuel efficiency and emission regulations, but in the case of electric vehicles, since there are no emission regulations and since the personalization of the driving system feel has a significantly smaller impact on power consumption than with an internal combustion engine, the virtual driving system feel can be actively personalized, thereby improving the vehicle's feel quality.

[0034] Therefore, the embodiments of the present disclosure disclose a control device and method for an electric vehicle, which can provide a different driving experience to the driver in the electric vehicle by establishing a virtual driving system model and realizing the features of other driving systems based on motor torque control.

[0035] Specifically, an embodiment of the present invention discloses a control device and method for realizing a virtual driving system feeling of an electric vehicle, wherein a driver can directly and freely change and adjust model setting variable values ​​(which are driver setting variable values ​​described later) related to the generation and realization of the virtual driving system feeling, thereby providing the driver with his or her favorite virtual driving system feeling and characteristics.

[0036] In the following description, the motor refers to a driving motor for driving a vehicle, and in an embodiment of the present disclosure, the vehicle to be controlled may be an electric vehicle equipped with a reducer without an internal combustion engine (ie, a conventional engine) and a multi-speed transmission.

[0037] In an embodiment of the present disclosure, the driving system feeling or the driving system driving feeling may mean including vibration of the driving system, wherein the driver can feel the vibration according to the control and driving state of the driving system in the vehicle while driving.

[0038] In an embodiment of the present disclosure, the vibration of the driving system may mean the vibration (i.e., change) of the motor torque (i.e., driving force) that the driver can feel, and when there is the vibration of the motor torque while driving, the driver can feel the vibration of the motor torque as the vibration of the vehicle. In order to achieve such vibration of the driving system, a motor torque command including a vibration component may be generated and applied.

[0039] That is, as described later, a virtual driving system torque command is generated and applied, which has vibration characteristics of predetermined frequency, damping ratio, and amplitude and has a value that changes in the form of vibration, and the torque output of the drive motor is controlled according to the virtual driving system torque command, so that the desired vibration of the virtual driving system can be generated.

[0040] In addition, personalization of the virtual driving system feeling refers to the driver directly changing and adjusting the set values ​​of variables related to the generation and realization of the virtual driving system feeling (i.e., driving feeling), thereby generating and realizing a separately differentiated virtual driving system feeling corresponding to the changed set values.

[0041] Hereinafter, embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings.

[0042] Figure 1 is a block diagram showing a structure of an apparatus for controlling an electric vehicle according to an embodiment of the present disclosure, and Figure 2 is a block diagram showing a state in which a torque command corrected by using a virtual driving system model is generated from a basic torque command in an embodiment according to the present disclosure. In addition, Figure 3 is a flowchart illustrating a process of executing a virtual driving system mode in an embodiment of the present disclosure.

[0043] According to an embodiment of the present invention, a control method for an electric vehicle includes: a change process, in which a driver directly changes variable setting values ​​of a virtual driving system model (i.e., a driver sets variable values) while a virtual driving system model for generating and realizing a virtual driving system feeling is constructed in a controller; and a control process, in which a driving system mode is operated, in which the driving system mode virtually generates and realizes a driving feeling of other driving systems (i.e., a virtual driving system feeling) by using the virtual driving system model when driving a vehicle.

[0044] In an embodiment of the present disclosure, a virtual driving system model is provided so that a driver can adjust and change model setting variable values ​​(ie, designated driver setting variable values) for personalization.

[0045] In addition, in the control process of the operation of the virtual driving system mode in the embodiment of the present disclosure, a virtual driving system torque command is generated by a virtual driving system model in which the set variable values ​​are changed, and the motor torque is controlled according to the generated virtual driving system torque command, thereby performing control processing for the motor to generate and realize a virtual driving system feeling (i.e., vibration) that is differentiated for each individual and preferred by the driver.

[0046] refer to Figure 3 , a control method according to an embodiment of the present invention is a control process for the operation of a virtual driving system mode, the control method comprising: a step S6 of determining the virtual driving system mode, wherein a controller determines whether the virtual driving system mode has been turned on by a driver; a step of determining a basic torque command, wherein when the virtual driving system mode is turned on, the controller determines the basic torque command according to vehicle driving information collected from the vehicle; a step of determining a corrected final torque command (i.e., a virtual driving system torque command), wherein a virtual driving system model that inputs the basic torque command in the controller determines the corrected final torque command according to the determined basic torque command to achieve a virtual driving system feel; and a step S7 of controlling the operation of a motor, wherein the operation of a motor as a driving device for driving the vehicle is controlled according to the final torque command determined in the controller.

[0047] In addition, the control method according to the embodiment of the present invention may also include the step of changing the driver setting variable value, wherein the driver setting variable value specified in the virtual driving system model is changed in the controller according to the change of the driver input. In the embodiment of the present disclosure, specifically, the change of the driver setting variable value may include: step S1, determining in the controller whether there is a change input of the driver setting variable value by the driver; step S2, when there is a change input, executing the change of the driver setting variable value in the controller according to the driver's input; step S3, determining in the controller whether the driver saves the selected changed driver setting variable value; and step S5, when saving is selected, applying the changed driver setting variable value to the virtual driving system model in the controller.

[0048] As described above, after saving the changed driver setting variable values ​​and applying the changed setting variable values ​​to the virtual driving system model, the virtual driving system model is used to determine a final torque command (i.e., a virtual driving system torque command) corrected according to the basic torque command, in which the driver setting variable values ​​are changed during starting the electric vehicle in an on-state of the virtual driving system mode, and the operation of the motor that drives the vehicle according to the determined final torque command is controlled (see step S7).

[0049] In addition, when there is no driver input for changing the set variable value in step S1, the sequence moves to step S6, and when there is no selection to save the changed driver set variable value in step S3, the sequence moves to step S6 after returning the variable value to the previously saved value. When the function of the virtual driving system mode is in the off state in step S6, the controller controls the operation of the motor according to the determined basic torque command (see step S8).

[0050] Furthermore, in describing the configuration of the control device for executing the motor control process for the virtual driving system mode according to the embodiment of the present disclosure, as Figure 1 As shown, the control device includes: an interface portion 11, which is configured to allow the driver to select and input one of the on and off modes of the virtual driving system of the vehicle, and to allow the driver to change and input driver-set variable values ​​for functional personalization of the virtual driving system mode; a driving information detector 12, which is used to detect vehicle driving information; a first controller 20, which is used to determine a basic torque command based on the vehicle driving information detected by the driving information detector 12, and to generate and output a virtual driving system torque command by using a virtual driving system model based on the determined basic torque command; and a second controller 30, which controls the operation of the driving device 41 according to the virtual driving system torque command output from the first controller 20.

[0051] Here, the first controller 20 can be configured to include: a basic torque command generating unit 21, for determining a basic torque command based on vehicle driving information collected from the vehicle; and a virtual driving system mode control unit 22, for generating and outputting a virtual driving system torque command by using a virtual driving system model based on the basic torque command determined by the basic torque command generating unit 21.

[0052] In the following description, the control agent is divided into the first controller 20 and the second controller 30, but the control process according to the embodiment of the present disclosure can be performed by an integrated control component instead of a plurality of controllers. When a plurality of controllers or an integrated control component are collectively referred to as a controller, it can be understood that the control process according to the embodiment of the present disclosure is performed by the controller. That is, the controller can be collectively referred to as a first controller and a second controller.

[0053] In the control device that performs the control process according to the embodiment of the present disclosure, any device can be applied to the interface part 11 as long as the device enables the driver to operate to select the on or off of the virtual driving system mode in the vehicle, and can change the driver setting variable value of the virtual driving system model by inputting the required driver setting variable value for personalization. For example, the interface part can be an operation device such as a button or switch provided in the vehicle, and an input device of an ANV (audio, video, navigation) system or a touch screen.

[0054] The interface portion 11 may be connected to the first controller 20, and therefore, when there is an on or off operation by the driver or a change operation of the driver setting parameter information by the driver, a signal according to the operation in the interface portion 11 may be input to the first controller 20. Therefore, the first controller 20 may recognize a state of on or off of the virtual driving system mode being operated by the driver and a state of changing the driver setting variable information by the driver.

[0055] In the embodiment of the present disclosure, only when the driver turns on the virtual driving system mode through the interface unit 11, the operation of the virtual driving system mode and its control processing are performed, and the operation of the virtual driving system mode and its control processing are used to generate and realize the virtual driving system feeling (which may be the virtual driving system vibration) through the motor torque control during the driving of the vehicle, see Figure 3 Step S6 in .

[0056] Furthermore, when the interface unit 11 is a vehicle input device provided in a vehicle, although Figure 1 Although not shown in the figure, the driver can also perform the operation of turning on or off the virtual driving system mode or changing the driver setting variable information through a mobile device (not shown) instead of such a vehicle input device.

[0057] The mobile device should be communicatively connected to the vehicle-mounted device (eg, the first controller 20 ), and for this purpose, an input / output communication interface (not shown) for communication connection between the mobile device and the first controller 20 is used.

[0058] The driving information detector 12 is a component that detects vehicle driving information required for a motor torque command generated in the vehicle, wherein the vehicle driving information may include driver's driving input information and vehicle state information.

[0059] In an exemplary embodiment of the present disclosure, the driving information detector 12 may include an accelerator pedal detector for detecting accelerator pedal input information according to the driver's accelerator pedal operation, and a brake pedal detector for detecting brake pedal input information according to the driver's brake pedal operation. In addition, the driving information detector 12 may also include a motor speed detector for detecting the rotation speed of a motor of a driving device 41 serving as a driving vehicle (hereinafter referred to as "motor speed").

[0060] Here, the accelerator pedal detector may be a conventional accelerator pedal sensor (i.e., accelerator position sensor, APS) installed on the accelerator pedal and outputting an electrical signal according to the driver's accelerator pedal operation state. The brake pedal detector may be a conventional brake pedal sensor (BPS) installed on the brake pedal and outputting an electrical signal according to the driver's brake pedal operation state. In addition, the motor speed detector may be a known rotary transformer installed in the motor (i.e., drive motor) 41.

[0061] At this time, the driver's driving input information 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, and the vehicle state information includes a motor speed detected by a motor speed detector.

[0062] In addition, in the basic torque command generating unit 21 described later, the driving information used to generate the basic torque command may also include the vehicle speed as the vehicle state information. In this case, the driving information detector 12 also includes a vehicle speed detector for detecting the driving speed of the vehicle, wherein the vehicle speed detector may be configured to include a wheel speed sensor mounted on the driving wheels of the vehicle.

[0063] The basic torque command may be a motor torque command determined and generated based on vehicle driving information collected in a general electric vehicle during driving, and the basic torque command generating unit 21 may be a vehicle control unit (VCU) that generates a motor torque command based on vehicle driving information in a general electric vehicle, or a part of the vehicle control unit.

[0064] In addition, the virtual driving system mode control unit 22 is a novel component that determines, generates and outputs a virtual driving system torque command based on a basic torque command by using a virtual driving system model. In the virtual driving system model, in an embodiment of the present disclosure, while receiving the basic torque command as input, the set variable information can be changed by the driver, and the virtual driving system mode control unit 22 can be added as a part of a vehicle control unit (VCU), or can be provided as a control component separate from the vehicle control unit.

[0065] The second controller 30 is a controller that controls the operation of the drive device 41 by receiving the final torque command output from the first controller 20 (ie, the virtual driving system torque command determined, generated, and output by the virtual driving system mode control portion 22 of the first controller 20 ).

[0066] In the embodiment of the present disclosure, the driving device 41 is a motor that drives the vehicle (ie, a driving motor), and the second controller 30 may be a motor control unit (MCU) that drives the motor through an inverter and controls the operation of the motor in a conventional electric vehicle. Figure 1 As shown, the torque and rotational force output from the driving device 41 are transmitted to the driving wheel 43 via the speed reducer 42 .

[0067] Meanwhile, in the embodiment of the present disclosure, a virtual driving system model capable of determining and generating a virtual driving system torque command by inputting a basic torque command is input in advance and set in the virtual driving system mode control portion 22 .

[0068] As described above, while the virtual driving system model is set in the virtual driving system mode control unit 22, during the operation of the virtual driving system mode, when the basic torque command is input from the basic torque command generation unit 21 to the virtual driving system mode control unit 22, the virtual driving system torque command is generated by correcting the basic torque command according to the driver setting variable information in the virtual driving system model of the virtual driving system mode control unit 22.

[0069] Therefore, the driving force generated by the vehicle during operation of the virtual driving system mode is not the basic torque command, but the driving force generated by the motor 41 operating according to the virtual driving system torque command, so that the driver can experience the feeling and characteristics of the virtual driving system through the driving force generated by the motor 41 according to the virtual driving system torque command.

[0070] Specifically, in the virtual driving system model, the driver can adjust the driver setting variable value to a value he or she wants, and the virtual driving system torque command is determined and output according to the driver setting variable value adjusted by the driver in the virtual driving system model.

[0071] Therefore, by adjusting the driving setting variable value by the driver, the driving force generated and output from the motor 41 can be distinguished even under the same vehicle driving conditions, and the personalization of the virtual driving system feel can be achieved, in which the driver is provided with a personalized feel and characteristics of the virtual driving system.

[0072] In an exemplary embodiment of the present disclosure, the driver-set variable information in the virtual driving system model may include at least one or more of the stiffness of the virtual driving system (i.e., the elasticity k), the damping amount of the virtual driving system (i.e., the damping rate d), and the inertia of the virtual driving system (i.e., the weight (mass m) of the virtual driving system).

[0073] Furthermore, in an exemplary embodiment of the present disclosure, when the realization of the virtual driving system feeling is the realization of the driving system vibration controlled by the motor torque, the driver setting variable information in the virtual driving system model may include the vibration frequency (i.e., the resonance frequency f) of the virtual driving system torque (which is the command). n ), at least one or more of the damping ratio of the virtual driving system torque (ie, the damping ratio ζ), and the amplitude of the virtual driving system torque (ie, the amplitude A).

[0074] The driver setting variable information is used to establish a virtual driving system model and is further used to convert the basic torque command into a virtual driving system torque command in the virtual driving system model during operation in the virtual driving system mode.

[0075] In addition, the driver setting variable value of the virtual driving system model can be adjusted by the driver to a value desired by the driver himself or herself through the interface unit 11, and the virtual driving system torque command converted from the basic torque command changes according to the driver adjusted value. Therefore, when the motor 41 is controlled according to the converted virtual driving system torque command, a differentiated virtual driving system feeling can be provided to the driver.

[0076] In an exemplary embodiment of the present disclosure, Figure 2 1 is a diagram showing that the virtual driving system model of the virtual driving system mode control section 22 generates and outputs a virtual driving system torque command as a correction torque command by inputting the basic torque command generated and output by the basic torque command generation section 21 .

[0077] Hereinafter, the virtual driving system model will be described in more detail.

[0078] In the embodiment of the present disclosure, a virtual driving system model for operation of the virtual driving system mode is preset in the virtual driving system mode control portion 22 , and the virtual driving system model is set to output a virtual driving system torque command by inputting a basic torque command.

[0079] In addition, in an embodiment of the present disclosure, a virtual driving system model is used to convert a basic torque command without a vibration component into a virtual driving system torque command including a vibration component, and in the virtual driving system model, the basic torque command is converted into a virtual driving system torque command using the above-mentioned driver setting variable value.

[0080] In conventional vehicles, control methods for driving force or torque are aimed at eliminating vehicle vibration, but in the embodiment of the present disclosure, driving force control or torque control is performed in which vibration can be increased in a desired form.

[0081] In an exemplary embodiment of the present disclosure, a mass-spring-damper system model is basically used as a virtual driving system model. In an exemplary embodiment of the present disclosure, when a conventional mass-spring-damper system model is used as a virtual driving system model, a basic torque command (which is an input torque command of the model) is replaced with an input force to be used in the mass-spring-damper system.

[0082] In addition, in an exemplary embodiment of the present disclosure, when a traditional mass-spring-damper system model is used as a virtual driving system model, the sum of the spring force and the damping force in the mass-spring-damper system becomes the virtual driving system torque command (i.e., the correction torque command), which is the output torque command of the model.

[0083] Here, the traditional mass-spring-damper system model refers to a system as shown in the following equation 1, where the sum (or difference) of the spring forces is the product of the displacement and the spring stiffness (i.e., elastic rate), the damping force is the product of the velocity (i.e., the differential value of the displacement) and the damping rate, and the input force is balanced by the product of the inertia (i.e., weight) and the acceleration (i.e., the differential value of the velocity).

[0084] When expressed mathematically, the above system is defined as the following differential equation:

[0085]

[0086] Among them, F in is the input force, k is the spring rate, d is the damping rate of the damper, m and x are the inertia (weight) and displacement of the mass, respectively, is speed and Acceleration.

[0087] In the above equation, kx represents the spring force, and Represents the damping force.

[0088] Furthermore, the output force is the sum of the spring force and the damping force ("output force=spring force+damping force"), the input force is the basic torque command, and the output force is the virtual driving system torque command.

[0089] In the virtual driving system model of equation 1, in an exemplary embodiment of the present disclosure, at least one or more k, d, and m become the above-mentioned driver-set variables, and these variables are variables that can be controlled by the driver, and in an embodiment of the present disclosure, the driver can adjust the driver-set variable values ​​through the interface unit 11.

[0090] That is, the driver may be allowed to adjust the stiffness (i.e., elasticity k) of the virtual driving system, the damping amount (i.e., damping rate d) of the virtual driving system, and the inertia (i.e., mass m) of the virtual driving system through the interface unit 11, which are driver-set variables. By adjusting these variable values, the characteristics of the virtual driving system model may be changed, and the form of the virtual driving system torque command corrected and converted according to the basic torque command may be changed.

[0091] k, d, and m are virtual physical values, respectively, and the driver can directly adjust the values ​​of direct parameters of the virtual driver system model such as k, d, and m. However, as a more intuitive personalization method, a function of adjusting the characteristics of the virtual driving system model can be provided by adjusting the values ​​of the derived parameters, rather than adjusting the virtual physical variables.

[0092] The natural vibration frequency of the virtual driving system torque (i.e., the resonance frequency f n ), the damping ratio of the virtual driving system torque (ie, the damping ratio ζ), and the amplitude of the virtual driving system torque (ie, the amplitude A) can be representatively defined as derived parameters. One advantage of this method is that each derived variable does not affect each other.

[0093] For example, when the k value increases, not only the vibration period speeds up, but also the damping is weakened even if the d value is fixed, so the variables affect each other. However, when the natural vibration frequency is increased, it is possible to speed up the vibration period and maintain the damping ratio.

[0094] In an exemplary embodiment of the present disclosure, the natural vibration frequency of the virtual driving system torque (ie, the resonance frequency f n ) is a variable that determines the frequency of the virtual driving system torque vibration, and the virtual driving system damping ratio (ie, damping ratio ζ) is a variable that determines the degree to which the vibration of the virtual driving system torque is damped and eliminated.

[0095] Furthermore, in the exemplary embodiment of the present disclosure, when describing the amplitude (A) of the virtual driving system torque, first, the amplitude of the virtual driving system torque is a variable that determines the magnitude of the torque vibration, and in a conventional mass-spring-damper system, the amplitude cannot be independently adjusted. The reason is that the amplitude is expressed as a function of the frequency and the damping ratio.

[0096] Therefore, an embodiment of the present disclosure proposes a method for adjusting the amplitude. A method of adjusting only the amplitude A of the vibration to be added while maintaining the value of the basic torque command (ie, input torque) is as follows.

[0097]

[0098] In Equation 2 above, m(2πf n ) 2 x corresponds to the spring force, and Here, the output torque (ie, the corrected and converted virtual driving system torque command) is as shown in Equation 3 below.

[0099]

[0100] In equation 3 above, is the basic torque command corresponding to the input force.

[0101] The above equation is expressed in terms of derived parameters and by this equation, the amplitude (A) can be related to the natural vibration frequency (i.e., the resonant frequency f n Here, the displacement (x) value is used as an intermediate variable for calculating the output torque, and the output torque (ie, the virtual driving system torque command) is used to control the driving force of the actual vehicle.

[0102] Figures 4 to 6 is a diagram showing an example of personalization and correction of a torque command in realizing a virtual driving system feel according to an embodiment of the present disclosure. Figures 4 to 6 , together with the basic torque command, a virtual driving system torque command obtained by converting the basic torque command using the driver setting variable information is shown.

[0103] Figure 4 is the natural vibration frequency (i.e., resonance frequency f) of the virtual driving system as the driver setting variable information. n ) by high frequency (high f n ), intermediate frequency (intermediate frequency n ), and low frequency (low f n ) values ​​are set differently.

[0104] Figure 5 It is a view showing an example in which the damping ratio (ζ) as the driver setting variable information of the virtual driving system is differently set by the values ​​of high damping ratio (high ζ), medium damping ratio (medium ζ), and low damping ratio (low ζ).

[0105] Figure 6It is a diagram showing an example in which the virtual driving system amplitude (ie, amplitude A) as the driver setting variable information is differently set to values ​​of high amplitude (High A), medium amplitude (Middle A), and low amplitude (Low A).

[0106] In addition to the above method of defining the amplitude A, another method of obtaining the final torque command by adjusting the amplitude A can also be used. The final corrected virtual driving system torque command can be obtained in the following manner, in which the difference between the corrected torque command and the basic torque command obtained by the above virtual driving system model is first obtained, the difference is multiplied by the set value of the amplitude A, which is the driver set variable value, and the multiplied value is added to the basic torque command. In other words, that is, a method of obtaining the difference between the input value and the output value of the virtual driving system model, multiplying the value by the set value of the amplitude A and adding it to the input value, and using the summed value as the final torque command (i.e., the final virtual driving system torque command).

[0107] In addition, another method of obtaining the final torque command can be applied by adjusting the amplitude A. There is a method in which the value of the output torque command (i.e., the first correction torque command) obtained by using the conventional mass-spring-damper system model as the virtual driving system model is input again to the virtual driving system model, and at this time, the output torque command obtained by the virtual driving system model is used as the value of the final torque command (i.e., the second correction torque command, which is the final virtual driving system torque command). That is, by using the virtual driving system model twice, it is possible to apply Figure 7 The method shown.

[0108] like Figure 7 As shown, a basic torque command (i.e., an input torque command) is input to a virtual driving system model to obtain a first correction torque command as an output torque command, and after applying predetermined weights to the first correction torque command and the basic torque command, respectively, the summed value is used as an input torque command of a second virtual driving system model. At this time, the amplitude A may be used as the weight of the first correction torque command. In addition, when the setting value of the amplitude A is large, the weight of the first correction torque command may be set to a value further increased than the weight of the basic torque command.

[0109] Meanwhile, in an exemplary embodiment of the present disclosure, a method for preventing signal divergence may be applied, wherein the output signal may diverge due to discretization error, system mathematical instability caused by a set value, etc. In order to prevent this problem, a range of personalized set values ​​without the risk of divergence may be defined, and the fluctuation of the set values ​​may be limited within these ranges. That is, a lower limit and a predetermined upper limit are predetermined and the predetermined lower limit and the predetermined upper limit are applied to each set value.

[0110] Even if a set value is applied within an allowable range due to a discrete error, it is possible to prevent a system signal from diverging, wherein after a divergent feature is detected, the divergent feature can be prevented by reducing the set value based on an overflow of the signal.

[0111] That is, when the signal value x or When the absolute value of is greater than a predetermined threshold, or when the sign of positive (+) / negative (-) changes at each sampling time, or when these phenomena continue for a predetermined time, the condition is determined to be divergent. In addition, when it is determined to be a divergent state, the natural vibration frequency (i.e., the resonance frequency f) set by the driver or already set is reduced in a predetermined manner compared to the value at the previous sampling time. n ) and the damping ratio (ζ). Repeat the reduction measure until the divergence condition ends.

[0112] In addition, in an exemplary embodiment of the present disclosure, when a virtual driving system torque command is used, a method for solving the driving system backlash problem can be applied. Near the case where the torque value switches between the driving direction and the regeneration direction (i.e., close to zero torque), backlash impact can occur with the change in the arrangement direction of the driving system gears. To prevent this problem, vibration can be eliminated only in a limited backlash section where backlash impact may occur.

[0113] As a method for solving this problem, a method of adjusting the amplitude A may be applied. When the basic torque command enters a predetermined backlash section, the amplitude A is reduced to a value of 0, and then when the basic torque command leaves the backlash section, the reduced amplitude A may be restored to the original set value. A rate limit or filter may be applied to the amplitude A adjusted in the process of reducing and restoring the amplitude A, and the virtual driving system torque command may be determined by using the amplitude A to which the rate limit or filter has been applied.

[0114] In an exemplary embodiment of the present disclosure, to explain the backlash section more, when the direction of the motor torque changes, an impact caused by the gear backlash may occur in a driving system including a speed reducer. Therefore, the backlash section may be preset in the controller as a section (including zero (0) torque) where a predetermined torque range (i.e., torque band) is close to zero torque.

[0115] At this time, the backlash section is composed of a negative (-) torque area and a positive (+) torque area divided based on zero (0) torque. That is, the backlash section may be referred to as a torque section in which a predetermined negative (-) torque value is set as a minimum value and a predetermined positive (+) torque value is set as a maximum value. In addition, the backlash section may be set for each driving system rotation speed or torque area.

[0116] In the embodiment of the present disclosure, the fact that the direction of the motor torque is switched means that the motor torque is converted from a positive (+) value to a negative (-) value, or conversely, from a negative value to a positive value. Here, the positive (+) motor torque represents the driving torque, and the negative (-) motor torque represents the regenerative torque.

[0117] In addition, in an exemplary embodiment of the present disclosure, a method using a transfer function model can be applied. Since the virtual mass-spring-damper system can be expressed as a linear system in the form of a transfer function, the entire virtual transmission system model can be converted into a transfer function for ease of application. As described above, the input of the transfer function is also a basic torque command, and the output of the transfer function is a virtual driving system torque command as a correction torque command. The method of converting a mass-spring-damper linear system into a transfer function is a well-known method, and therefore a detailed description will be omitted here.

[0118] Figure 8 is a view showing examples of various torque forms according to setting values ​​of natural vibration frequencies and damping ratios in an embodiment of the present disclosure, and exemplary embodiment 1 shows daily driving and comfort modes that provide sufficient acceleration / deceleration response and smooth driving.

[0119] Exemplary embodiment 2 is an example of achieving the feeling of a high-performance GT car (i.e., a large tourer), and is an example of providing driving performance without great inconvenience for long-distance travel even if quick responsiveness is important. Exemplary embodiment 3 is an example of achieving the feeling of a sports car, and is an example of providing an intuitive twisting feeling of a driving system due to immediate acceleration / deceleration response and strong torque output.

[0120] Exemplary embodiment 4 is an example of realizing the feeling of a large vehicle such as a bus, and is an example of providing the feeling of low-frequency vibration caused by large gear backlash and high inertia. Exemplary embodiment 5 is an example of providing a gentle acceleration / deceleration feeling without a step by removing a sharp driving input, and exemplary embodiment 6 is an example of providing a feeling similar to inducing a baby to sleep with continuous and smooth movement in the front and rear directions while fully reflecting the driver's will.

[0121] In this way, according to the control method of the embodiment of the present disclosure described above, various characteristics that can be provided by other driving systems such as the driving system of an internal combustion engine vehicle are virtually realized and simulated using the motor in the electric vehicle according to the driver's request.

[0122] Although vibration can be generated by simply adding a continuous vibration pattern determined according to a set value, in this case, an unrealistic vibration may be provided to the driver. Therefore, in an embodiment of the present disclosure, a virtual driving system model is used to add a vibration torque that reflects the driver's acceleration / deceleration intention.

[0123] As a result, according to an embodiment of the present disclosure, highly realistic vibration torque can be achieved, the driver can feel a driving feeling as if the driving system of the actual vehicle has been changed through adjustment, rather than feeling a simple vibration, and unique vehicle marketability can be provided that allows the driver to experience not only the driving system of his or her own vehicle, but also the driving systems of various vehicle types.

[0124] Although the embodiments of the present disclosure have been described in detail as above, the scope of the present disclosure is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present disclosure defined in the appended claims are also included in the scope of the present disclosure.

Claims

1. A control method for an electric vehicle for realizing a virtual driving system experience, the control method comprising: determining, by the controller, a basic torque command for controlling operation of the drive motor based on vehicle driving information collected while driving the vehicle; The controller determines a virtual driving system torque command corrected from the basic torque command based on adjusting and changing a model setting variable value of a preset virtual driving system model, thereby realizing the virtual driving system feeling; and The controller controls the torque of the driving motor according to the virtual driving system torque command.

2. The control method according to claim 1, wherein: The virtual driving system torque command obtained by adding a vibration component to the basic torque command is a motor torque command having a value that changes in a vibration form.

3. The control method according to claim 1, wherein: The model setting variable value is a driver setting variable value, and the control method further includes: The driver setting variable value preset in the virtual driving system model is changed by the controller, and the virtual driving system model is used to determine the virtual driving system torque command based on the basic torque command according to the change input of the driver.

4. The control method according to claim 3, wherein: The virtual driving system torque command obtained by adding a vibration component to the basic torque command is a motor torque command having a value that changes in a vibration form, and The driver setting variables determined in the virtual driving system model include at least one or more of a vibration frequency of the virtual driving system torque command, a damping ratio of the virtual driving system torque command, and an amplitude of the virtual driving system torque command.

5. The control method according to claim 4, wherein: A mass-spring-damper system model is used as the virtual driving system model in the controller.

6. The control method according to claim 4, wherein: When determining the virtual driving system torque command, the correction torque command is determined by the virtual driving system model by inputting the basic torque command, and The virtual driving system torque command is determined by adding the basic torque command to a value obtained by multiplying a difference value, which is a difference between the correction torque command and the basic torque command, by the amplitude, the amplitude being the driver set variable value.

7. The control method according to claim 4, wherein: When determining the virtual driving system torque command, a first correction torque command is determined by inputting the basic torque command, wherein the first correction torque command is obtained by correction of the virtual driving system model; After applying respective predetermined weights to the first correction torque command and the basic torque command, obtaining a sum value; By inputting the sum value, a second corrected torque command corrected by the virtual driving system model is determined as the virtual driving system torque command; and The weight applied to the first correction torque command is the amplitude as the driver set variable value.

8. The control method according to claim 4, wherein: In the controller, when the base torque command enters a preset lash section, the amplitude is reduced to a zero value, and when the base torque command leaves the preset lash section, the amplitude is restored to a value set by the driver.

9. The control method according to claim 8, wherein: The preset backlash section is set as a section where the torque range is approximately the zero value, and is set as a torque section in which a predetermined negative torque value is a minimum value and a predetermined positive torque value is a maximum value.

10. The control method according to claim 4, wherein: A mass-spring-damper system model is used as the virtual driving system model in the controller, wherein the virtual driving system torque command is given by the equation: spring force + damping force - (A-1) is determined, in which A is the amplitude of the virtual driving system torque command, and is the basic torque command.

11. The control method according to claim 3, wherein: The controller uses a mass-spring-damper system model as the virtual driving system model, wherein an input force is the basic torque command, and an output force which is a sum of a spring force and a damping force is the virtual driving system torque command.

12. The control method according to claim 11, wherein: The equation representing the mass-spring-damper system model is In the equation, the product of displacement x and elastic modulus k is the spring force, speed The product of the speed and the damping rate d is the damping force, the speed is the differential value of the displacement, and The determined driver setting variable is at least one or more of the spring rate k, the damping rate d, and the mass m.

13. A control device for an electric vehicle for realizing a virtual driving system experience, the control device comprising: A first controller, generating and outputting a virtual driving system torque command; as well as a second controller, controlling the torque of the driving motor according to the virtual driving system torque command output from the first controller, Wherein, the first controller comprises: a basic torque command generating section for determining a basic torque command and for controlling the operation of the drive motor according to vehicle driving information collected during driving of the vehicle; and a virtual driving system mode control unit for determining the virtual driving system torque command from the basic torque command determined by the basic torque command generating unit by using the set virtual driving system model in a state where a virtual driving system model has been preset, wherein the virtual driving system torque command is a correction torque command for realizing a virtual driving system feel, Wherein, the virtual driving system model is provided so that the interface part directly adjusts and changes the model setting variable value for the driver's personalization.

14. The control device according to claim 13, wherein: The virtual driving system torque command obtained by adding a vibration component to the basic torque command is a motor torque command having a value that changes in a vibration form.

15. The control device according to claim 13, further comprising: An interface portion is configured to allow a driver to input a change to a driver setting variable value determined in the virtual driving system model set in the virtual driving system mode control portion.

16. The control device according to claim 15, wherein: The virtual driving system torque command obtained by adding a vibration component to the basic torque command is a motor torque command having a value that changes in a vibration form, and The driver setting variables determined in the virtual driving system model include at least one or more of a vibration frequency of the virtual driving system torque command, a damping ratio of the virtual driving system torque command, and an amplitude of the virtual driving system torque command.

17. The control device according to claim 16, wherein: A mass-spring-damper system model is used as the virtual driving system model.

18. The control device according to claim 15, wherein: A mass-spring-damper system model is used as the virtual driving system model, and In the mass-spring-damper system model, the input force is the basic torque command, and the output force which is the sum of the spring force and the damping force is the virtual driving system torque command.

Images