Method for operating an electric vehicle having means for generating a virtual shift sensation and electric vehicle

Abstract

A method for operating an electric vehicle, wherein the electric vehicle comprises a drive unit with at least one electric motor (11), wherein the electric vehicle comprises means (13) for generating a virtual shift sensation, wherein a virtual upshift of the means (13) for generating a virtual shift sensation is prevented based on a reduction of the driver-side accelerator pedal position.

Description

Technical Field

[0001] This invention relates to a method for operating an electric vehicle having a device for generating a virtual gear shift feel. Furthermore, this invention relates to an electric vehicle having a device for generating a virtual gear shift feel. Background Technology

[0002] Electric vehicles are also known as battery electric vehicles. An electric vehicle's drive unit has at least one electric motor but no internal combustion engine. In motor vehicles whose drive unit has an internal combustion engine, a multi-speed manual transmission is connected between the internal combustion engine and the vehicle's output. For efficiency reasons, this multi-speed manual transmission is increasingly being designed as an automatic transmission. In an automatic transmission, gear changes are performed automatically based on driver-side operation of the accelerator pedal and / or the brake pedal. Furthermore, automatic transmissions are known to exist in which gear changes are also performed manually based on driver-side operation of sequential shift elements (e.g., paddle shifters).

[0003] In electric vehicles, there is no multi-speed manual transmission connected between the electric motor and the output; at most, a reduction gearbox, typically with a single fixed gear ratio or at most two gear ratios, is connected. Gear changes known to occur when switching from a motor vehicle with an internal combustion engine and a multi-speed manual transmission are not performed in electric vehicles. Therefore, drivers switching from internal combustion engine vehicles to electric vehicles often find the driving experience of electric vehicles less emotional.

[0004] As explained above, a motor vehicle designed as an electric vehicle has at least one electric motor as its drive unit, but no internal combustion engine. The electric vehicle has a traction battery in which electrical energy is stored to operate at least one electric motor. In a range-extended electric vehicle (REEV), this can be obtained via an internal combustion engine used to charge the traction battery; however, the internal combustion engine is not part of the drive unit in a REEV because, even in a REEV, only at least one electric motor at the output of the electric vehicle provides drive power, not the internal combustion engine. The same applies to fuel cell electric vehicles, in which the fuel cell is used to charge the traction battery.

[0005] US 2021 / 0 309 113 A1 discloses an electric vehicle having a device for generating a virtual shifting sensation.

[0006] DE 10 2022 211 435 A1 discloses another electric vehicle with a device for generating a virtual shifting sensation. Summary of the Invention

[0007] There is a need to further enhance the driving experience of electric vehicles. The problem addressed by this invention is to provide a method for operating an electric vehicle, as well as an electric vehicle itself.

[0008] This objective is achieved by the method for operating an electric vehicle according to claim 1 and the electric vehicle according to claim 10.

[0009] According to the present invention, virtual upshifting of the device used to generate virtual shifting sensation is prohibited based on the lowering of the accelerator pedal position on the driver's side.

[0010] The present invention can be used to further enhance the driving experience in electric vehicles equipped with devices for generating a virtual shift feel. In particular, it can provide the driver of an electric vehicle with a dynamic, responsive driving experience, such that downshifting is prohibited based on the position of the accelerator pedal on the driver's side, in order to provide a dynamic vehicle response to subsequent, more forceful manipulation of the accelerator pedal.

[0011] Preferably, when the amount of reduction in the driver's side accelerator pedal position and / or the amount of the time gradient of the reduction in the driver's side accelerator pedal position exceed a corresponding limit value, especially when the automatic operation mode of the device for generating virtual shift feel is activated and / or when the forward driving level is activated as the driving level, virtual upshifting of the device for generating virtual shift feel is prohibited. This is particularly preferred for enhancing the driving experience of electric vehicles equipped with devices for generating virtual shift feel.

[0012] Preferably, virtual upshifts using a device to generate a virtual shift feel are prohibited when the amount of the accelerator pedal position reduction on the driver's side, and the amount of the reduction in the electric vehicle's current driving speed and / or current driving mode, particularly when the amount of the accelerator pedal position reduction on the driver's side and / or the amount of the time gradient of the accelerator pedal position reduction on the driver's side, exceeds a corresponding limit based on the current driving speed and / or current driving mode. This is also particularly preferred for enhancing the driving experience of electric vehicles equipped with devices for generating virtual shift feel.

[0013] Preferably, when the amount of reduction in the accelerator pedal position on the driver's side and / or the amount of the time gradient of the reduction in the accelerator pedal position on the driver's side exceed the corresponding limit value, and furthermore, when the virtual engine speed exceeds the maximum speed, the corresponding virtual upshift of the device for generating the virtual shift feel is not prohibited but executed. If, as a result of suppressing upshift, the virtual engine speed exceeds the maximum speed, especially based on the current virtual shift, then an upshift is executed.

[0014] Preferably, a virtual downshift is performed when the amount of reduction in the accelerator pedal position on the driver's side and / or the amount of the time gradient of the reduction in the accelerator pedal position on the driver's side are greater than a corresponding limit value, and furthermore, when the virtual engine speed is lower than a minimum speed. A virtual downshift is performed if the virtual engine speed is lower than the corresponding minimum speed for the current virtual shift. Attached Figure Description

[0015] Preferred further embodiments of the invention are disclosed in the dependent claims and the following description. Exemplary embodiments of the invention will be explained in more detail with reference to the accompanying drawings, but are not limited thereto. The drawings show: Figure 1 It is an electric vehicle. Figure 2 This is a block diagram of the components of an electric vehicle. Detailed Implementation

[0016] Figure 1 A motor vehicle configured as an electric vehicle 10 is shown. In the electric vehicle 10, its drive unit has at least one electric motor 11, but no internal combustion engine. The drive unit of the electric vehicle 10 may have a single electric motor 11, which subsequently drives the axles of the electric vehicle 10. The drive unit of the electric vehicle 10 may also include multiple electric motors 11. For example, in the case of two driven axles of the electric vehicle 10, each driven axle may be assigned a separate electric motor 11, wherein the electric vehicle 10 has two electric motors 11.

[0017] Each driven wheel of the electric vehicle 10 may also be assigned a separate electric motor 11, wherein the number of electric motors 11 of the drive unit of the electric vehicle 10 corresponds to the number of driven wheels of the electric vehicle 10.

[0018] The number of electric motors 11 in the drive unit of the electric vehicle 10 is purely exemplary.

[0019] Figure 2 A highly schematic component of the electric vehicle 10 is shown, namely the electric motor 11, which provides drive power to the output terminal 12 of the electric vehicle 10.

[0020] In the electric vehicle 10, unlike internal combustion engine-driven motor vehicles, a multi-speed manual transmission is not connected between the electric motor 11 and the output terminal 12. Instead, a reduction gearbox with a single fixed gear ratio or two gear ratios is connected at most. Therefore, in the electric vehicle 10, gear changes are not performed by driver-side operation of the accelerator pedal and / or driver-side operation of the brake pedal, as is known in internal combustion engine motor vehicles. This limits the driving experience of the electric vehicle 10.

[0021] To enhance the driving experience of the electric vehicle 10, the electric vehicle 10 according to the present invention includes a device 13 for generating a virtual shifting sensation. The device 13 for generating the virtual shifting sensation can simulate a virtual gearbox with virtual shifting by controlling at least one electric motor 11 of the electric vehicle 10 in such a way that the at least one electric motor 11 provides a torque curve at its output end 12, the torque curve corresponding to the torque curve that would be formed when a gear change is performed in a motor vehicle driven by an internal combustion engine with a multi-speed manual gearbox.

[0022] When the device 13 for generating the virtual shift feel is deactivated, the electric vehicle 10 operates like a conventional electric vehicle without performing virtual shifts. On the other hand, if the device 13 for generating the virtual shift feel is activated, the device generates the virtual shift feel for the driver. Here, the device 13 for generating the virtual shift feel can preferably generate the virtual automatic shift feel in a first automatic operation mode, or generate the virtual manual shift feel in a second manual operation mode.

[0023] In the first automatic operation mode, device 13 simulates the presence of an automatic multi-gear transmission, such that device 13, used to generate a virtual shift feel, performs virtual automatic shifting based on driver-side operation of the accelerator pedal 18 and / or driver-side operation of the brake pedal (not shown), and provides the torque curve that would be formed at output 12 in the presence of an automatic multi-gear transmission by controlling the electric motor 11 at output 12. Accelerator pedal 18 is also referred to as the accelerator pedal.

[0024] The driver requests driver-side control based on the accelerator pedal 18 and the brake pedal (not shown).

[0025] In the first automatic operation mode, the torque curve provided at the output terminal 12 can be determined in a characteristic curve-based manner by the device 13 for generating virtual shift feel based on the operation of the accelerator pedal 18 and / or the operation of the brake pedal, and in particular also based on the virtual current gear and virtual target gear of the corresponding virtual shift to be performed.

[0026] On the other hand, when the second manual operation mode of the device 13 for generating virtual shift feel is activated, the device 13 specifically generates virtual manual shift feel based on the driver-side operation of sequential shift elements 15, 16 mounted on the steering wheel 14 of the electric vehicle, which can be implemented as paddle shifters in the illustrated exemplary embodiment. If the second manual operation mode of the device 13 for generating virtual shift feel is activated, the device 13 controls the electric motor 11 according to the driver-side operation of the sequential shift elements 15, 16, causing it to perform the same virtual sequential shift, and provides at the output terminal 12 a torque curve that would be formed in the case where a multi-speed manual transmission operating in sequential shift mode or operation mode exists in the electric vehicle 10.

[0027] In the second manual operation mode, the torque curve provided at the output end 12 can be specifically determined by the device 13 for generating a virtual shift feel in a characteristic curve-based manner according to the operation of the shift elements 15, 16 in the corresponding sequence.

[0028] Therefore, the device 13 of the electric vehicle 10 for generating a virtual shifting sensation simulates the existence of the multi-speed manual transmission based on the operating mode of the multi-speed manual transmission.

[0029] When the device 13 of the electric vehicle 10 for generating a virtual shifting sensation is activated, it can preferably operate in two operating modes, namely, as described above, in a first automatic operating mode or a second manual operating mode.

[0030] Therefore, when the device 13 for generating the virtual shift feel is deactivated, the motor vehicle behaves like a conventional electric vehicle, does not simulate virtual shifting, and does not provide the virtual shift feel. On the other hand, if the device 13 for generating the virtual shift feel is activated, the device provides the virtual shift feel depending on the activated operating mode, in which the device simulates a virtual gearbox, specifically by controlling the electric motor 11 in such a way that the device provides at its output end 12 the torque curve that would be formed when performing a gear change in a multi-speed manual transmission of an internal combustion engine vehicle.

[0031] The device 13 for generating a virtual shifting sensation not only simulates a virtual gearbox but also a virtual internal combustion engine, performing virtual shifting based on its virtual engine speed and / or virtual torque, especially in the first automatic shifting mode.

[0032] If, in the first automatic operation mode, driver-side operation based on the accelerator pedal 18 and / or driver-side operation based on the brake pedal reaches a virtual shift point based on the virtual engine speed and / or the virtual torque of the virtual internal combustion engine, a virtual shift can be performed. This is specifically accomplished through the virtual shift characteristic curve of the virtual shift strategy in a characteristic curve-based manner.

[0033] The virtual engine speed of the virtual internal combustion engine can be simulated by a device 13 for generating a virtual shifting sensation, in that the virtual engine speed of the virtual internal combustion engine is calculated based on the known drive speed or rotational speed or the rotational speed of the electric motor 11 at the control side at the output end 12 of the electric vehicle 10 and the virtual gear ratio of the engaged virtual shift.

[0034] Based on the virtual engine speed of the virtual internal combustion engine calculated in this manner, the device 13 for generating a virtual shifting sensation can determine the virtual torque of the virtual internal combustion engine based on a characteristic curve or a feature line, i.e., based on the virtual engine characteristic curve of the virtual internal combustion engine.

[0035] Figure 2 A driving direction selector 17 for the electric vehicle 10 is also shown. The driving direction selector 17 allows selection of the driver's side driving level, such as forward driving level D, reverse driving level R, or neutral N.

[0036] As discussed above, in the automatic operation mode of the device 13 for generating virtual shift feel, virtual shifting is automatically performed based on driver-side operation of the accelerator pedal 18 and driver-side operation of the brake pedal (not shown). In the context of this invention, virtual upshifting by the device 13 for generating virtual shift feel is prohibited based on the reduction of the driver-side accelerator pedal position 18, i.e., such virtual upshifting is not performed, particularly when the amount of reduction of the driver-side accelerator pedal position and / or the amount of the time gradient of the reduction of the driver-side accelerator pedal position exceeds a corresponding limit value.

[0037] Based on the reduction of the accelerator pedal position on the driver's side of the accelerator pedal 18, and further based on the current driving speed of the electric vehicle 10 and / or based on the current driving mode, virtual upshifts of the device 13 used to generate virtual shift sensations are prohibited. Specifically, limits are provided for the amount of reduction of the driver's side accelerator pedal position and / or the amount of the time gradient of the reduction of the driver's side accelerator pedal position, determined particularly in a characteristic curve-based manner, based on these limits, and virtual upshifts of the device 13 used to generate virtual shift sensations are prohibited based on these limits.

[0038] For example, for the economy driving mode, range driving mode, sport driving mode, performance driving mode, or racing driving mode of the electric vehicle 10, different limit values ​​can be maintained at the same driving speed. Based on these different limit values, virtual upshifts by the device 13 used to generate a virtual shift feel are prohibited when the accelerator pedal 18 is lowered on the driver's side. Similarly, for each of these driving modes of the electric vehicle 10, the corresponding limit values ​​can be changed, particularly via corresponding characteristic curves in a speed-based manner, to provide different limit values ​​at different driving speeds, and then virtual upshifts are prohibited based on the lowering of the accelerator pedal position on the driver's side according to these different limit values.

[0039] When the device 13 for generating a virtual shift feel is running in automatic shift mode and the forward driving level D is activated as the driving level, this virtual upshifting of the device 13 for generating a virtual shift feel occurs based on the reduction of the accelerator pedal position on the driver's side.

[0040] By disabling virtual upshifts of the device 13 used to generate a virtual shift feel based on the lowering of the accelerator pedal position on the driver's side, the time delay between the deceleration and acceleration phases of the electric vehicle 10 can be reduced, so as to provide a particularly dynamic or sporty driving experience in the electric vehicle 10.

[0041] Specifically, in this invention, the amount of accelerator pedal position reduction is evaluated, and additionally, the temporal gradient of the accelerator pedal position reduction is evaluated. If the temporal gradient of the accelerator pedal position reduction on the driver's side is large in its summation, the accelerator pedal position changes rapidly. For the amount of the temporal gradient of the accelerator pedal position reduction on the driver's side, a corresponding limit value is preferably stored, and when said corresponding limit value is reached or exceeded, virtual upshifting of the device 13 used to generate virtual shift feel is prohibited. Therefore, when virtual upshifting of the device 13 used to generate virtual shift feel is prohibited, both the amount of change in accelerator pedal position and the amount of the temporal gradient of the change in accelerator pedal position are preferably considered.

[0042] When upshift suppression is implemented based on the lowering of the accelerator pedal position on the driver's side, and the virtual engine speed exceeds the maximum speed (which is specifically based on the current virtual gear of the device 13 for generating the virtual shift feel), the device 13 for generating the virtual shift feel does not prohibit but instead performs a virtual upshift. If upshift suppression is implemented due to the lowering of the accelerator pedal position on the driver's side, and the virtual engine speed exceeds the minimum speed, the device 13 for generating the virtual shift feel performs a virtual downshift.

[0043] Based on the suppression of virtual upshifts by the device 13 used to generate a virtual shift feel, torque control of the electric motor 11 can also be adapted to ensure instant responsiveness when operating the accelerator pedal 18. This is done while taking into account and ensuring driving control or driving stability.

[0044] In a further development of the invention, optical and / or auditory feedback is provided to the driver regarding the suppression of virtual upshifts. For example, the corresponding feedback may be displayed in the instrument panel of an electric vehicle or in the central display screen of the electric vehicle.

[0045] The suppression of virtual upshifts in the device 13 used to generate a virtual shift feel, based on the lowering of the accelerator pedal position on the driver's side, only occurs when the forward driving level D is activated as the driving level. If the forward driving level D is no longer activated, the suppression of virtual upshifts ends based on the lowering of the accelerator pedal position on the driver's side.

[0046] The suppression of upshifting ends even when the amount of reduction in the accelerator pedal position on the driver's side and / or the amount of reduction in the time gradient on the driver's side no longer exceed the corresponding limit value.

[0047] Furthermore, when virtual upshifting begins to be prohibited due to the amount of reduction in the driver's side accelerator pedal position and / or the amount of the time gradient of the reduction in the driver's side accelerator pedal position becoming greater than the corresponding limit value, a timer can be started, and the prohibition of virtual upshifting can be ended when the timer stops.

[0048] As discussed above, the virtual upshift prohibition can be terminated based on the virtual engine speed. If the virtual engine speed is greater than the maximum speed of the current virtual gear, specifically based on the device 13 used to generate the virtual shift feel, then the upshift prohibition is terminated and a virtual upshift is performed, thereby reducing the virtual engine speed.

[0049] This invention relates to electric vehicles having a drive unit including at least one electric motor 11 and a device 13 for generating a virtual gear shift feel. The device 13 of the electric vehicle 10 is configured to disable virtual upshifts in the manner described above based on a decrease in the position of the accelerator pedal on the driver's side. Using this invention, a sporty driving behavior can be provided when the accelerator pedal position is rapidly lowered, particularly for enabling subsequent acceleration when transitioning to a subsequent acceleration phase with high power.

Claims

1. A method for operating an electric vehicle (10), in, The electric vehicle (10) includes a drive unit having at least one electric motor (11). The electric vehicle (10) includes a device (13) for generating a virtual gear shifting sensation. Its features The virtual upshifting of the device (13) used to generate the virtual shifting sensation is prohibited by lowering the position of the accelerator pedal on the driver's side.

2. The method according to claim 1, characterized in that, When the amount of reduction in the accelerator pedal position on the driver's side and / or the amount of the time gradient of the reduction in the accelerator pedal position on the driver's side are greater than the corresponding limit value, the virtual upshift of the device (13) for generating virtual shift feel is prohibited.

3. The method according to claim 1 or 2, characterized in that, Virtual upshifts of the device (13) used to generate a virtual shift feel are prohibited based on the lowering of the accelerator pedal position on the driver's side and based on the current driving speed of the electric vehicle (10) and / or based on the current driving mode.

4. The method according to claim 3, characterized in that, Virtual upshifting of the device (13) for generating virtual shift feel is prohibited when the amount of reduction in the accelerator pedal position on the driver's side and / or the amount of the time gradient of the reduction in the accelerator pedal position on the driver's side is greater than the corresponding limit value based on the current driving speed and / or the current driving mode.

5. The method according to any one of claims 1 to 4, characterized in that, When the amount of reduction in the accelerator pedal position on the driver's side and / or the amount of the time gradient of the reduction in the accelerator pedal position on the driver's side are greater than the corresponding limit value, and furthermore, when the virtual engine speed exceeds the maximum speed, the virtual upshift of the device (13) for generating virtual shift feel is not prohibited but executed.

6. The method according to any one of claims 1 to 5, characterized in that, When the amount of reduction in the accelerator pedal position on the driver's side and / or the amount of the time gradient of the reduction in the accelerator pedal position on the driver's side are greater than the corresponding limit value, and in addition when the virtual engine speed is lower than the minimum speed, the virtual downshift of the device (13) for generating virtual shift feel is performed.

7. The method according to any one of claims 1 to 6, characterized in that, When the automatic operation mode of the device (13) for generating virtual shifting sensation is activated, a virtual automatic shifting sensation is generated, and when the manual operation mode of the device (13) for generating virtual shifting sensation is activated, a virtual manual shifting sensation is generated.

8. The method according to claim 7, characterized in that, When the amount of reduction in the accelerator pedal position on the driver's side and / or the amount of the time gradient of the reduction in the accelerator pedal position on the driver's side are greater than the corresponding limit value, the virtual upshift of the device (13) for generating virtual shift feel is prohibited only when the automatic operation mode is activated.

9. The method according to any one of claims 1 to 8, characterized in that, When the amount of reduction in the accelerator pedal position on the driver's side and / or the amount of the time gradient of the reduction in the accelerator pedal position on the driver's side are greater than the corresponding limit value, the virtual upshift of the device (13) for generating virtual shift feel is prohibited only when the forward driving level is activated as the driving level.

10. An electric vehicle (10). It has a drive unit including at least one electric motor (11). It has a device (13) for generating a virtual shifting sensation. Its features The device (13) for generating a virtual shifting sensation is configured to prevent virtual upshifts based on the lowering of the accelerator pedal position on the driver's side.

11. The electric vehicle (10) according to claim 10, characterized in that, The device (13) for generating a virtual shifting sensation is configured to perform the method according to any one of claims 1 to 9.

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