Method for operating a motor vehicle

Abstract

The invention relates to a method for operating a motor vehicle, wherein the motor vehicle has a drive unit which is designed in such a way that, in the event of acceleration, the motor vehicle is accelerated with a stepless torque output, wherein, in accordance with the method, the drive unit can be operated in a first operating mode and in a second operating mode, wherein, in the first operating mode, the motor vehicle is accelerated in an uninterrupted manner by means of the stepless torque output, and wherein, in the second operating mode, the stepless torque output is converted into a stepped torque output, so that, in the second operating mode, the motor vehicle is accelerated in a discontinuous manner by means of the stepped torque output.

Description

Technical Field

[0001] The present invention relates to a method for operating a motor vehicle according to the type described in claim 1 of the patent. Background Technology

[0002] Motor vehicles with internal combustion engines equipped with multi-speed transmissions, which are currently widely used, are known to exhibit driving characteristics such as a brief interruption of traction during acceleration due to gear shifts, and the presence of audible shift signals due to torque changes.

[0003] In addition to the dynamic driving experience, the aforementioned effects (i.e., traction interruption and audible signals) generally make drivers feel that they are supportive aids that enhance their attention and focus on road events, which has a positive impact on road safety.

[0004] In continuously variable transmissions (CVTs), especially in electric vehicles which typically only have one gear stage, the aforementioned effects do not occur during acceleration; that is, there is no brief interruption of traction caused by gear shifting, nor a shift signal that can be perceived audibly. In some cases, the resulting decrease in attention can lead to driver fatigue, which in turn negatively impacts road safety.

[0005] DE 10 2009 035 779 A1 discloses a method for operating a transmission, particularly for a power-split hybrid transmission in a vehicle, especially a hybrid vehicle. This method allows the simulation of a transmission with a continuously variable transmission ratio as operating a conventional automatic transmission. This provides the vehicle driver with a pleasant driving experience familiar to conventional transmissions.

[0006] Other methods for operating motor vehicles can be found in DE 10 2014 216 678 A1, DE 10 2007 016420 B4 and DE 10 2008 001 805 A1. Summary of the Invention

[0007] Therefore, the object of the present invention is to describe a method for operating a motor vehicle with a drive unit having uninterrupted torque output, thereby reducing the risk of driver fatigue.

[0008] This objective is achieved through the features of claim 1 of the patent.

[0009] Dependent claims 2 to 8 form advantageous improvements to the method according to the invention.

[0010] According to the method of the present invention, the drive unit can operate in a first operating mode and a second operating mode, wherein in the first operating mode, the vehicle accelerates uninterruptedly by means of continuously variable torque output, while in the second operating mode, the continuously variable torque output is converted into a stepped torque output, so that the vehicle accelerates intermittently by means of stepped torque output in the second operating mode.

[0011] For the sake of completeness, it should be noted that uninterrupted acceleration of a motor vehicle is understood as an acceleration curve with a continuous (non-gradual) trend in an acceleration curve graph plotted with torque (Y-axis) relative to speed (X-axis). Conversely, interrupted acceleration is understood as an acceleration curve with a discontinuous (gradual) trend.

[0012] In the following text, a motor vehicle with a drive unit that provides uninterrupted torque output should be understood in particular as a vehicle with a continuously variable transmission or an electric vehicle.

[0013] By means of the method according to the invention, it is now ensured that, when the motor vehicle is operating in the second operating mode, a perceptible interruption of traction and an audible effect caused by torque changes occur during acceleration. The perceptible interruption of traction and the resulting audible effect have a positive impact on driver attention, i.e., reduce fatigue effects, which positively impacts road traffic safety. Another advantage is that the ability to switch between the two operating modes makes it easier for potential new customers of electric vehicles to upgrade.

[0014] In order to facilitate easy switching of operating modes, i.e., from the first operating mode to the second operating mode or from the second operating mode to the first operating mode, the switching is preferably performed after easy manual operation of the control element provided for this purpose.

[0015] Control elements could be, for example, a schaltpad del located on the steering wheel.

[0016] Preferably, the desired number of interruptions, n, can be set / adjusted in the second operating mode. That is, arbitrary gear shifting simulation can be provided, thus enabling "gear shifting without switching (Schalten ohneSchaltung)". Therefore, for example, a four-speed transmission can be simulated by selecting n=4.

[0017] Furthermore, it is preferable to be able to set / adjust the torque drop caused by the interruption in the second operating mode, that is, to set / adjust the intensity ΔM of the torque drop.

[0018] Another preferred embodiment is characterized by the ability to set / adjust the interruption duration t in the second operating mode. Setting the interruption duration, combined with setting the number of interruptions and the intensity of torque drop, enables realistic simulation tailored to specific needs in the second operating mode. Particularly advantageously, various modes, such as sport mode and comfort mode, are pre-set with corresponding values ​​for the number of interruptions n, the torque drop intensity ΔM during interruption, and the interruption duration t, and can be selected accordingly.

[0019] Preferably, in the second operating mode, an additional audible signal is also generated when torque output is interrupted. Since the interruption of torque output can now be perceived not only through the audible effect caused by the interruption of traction and torque change, but also through the generated additional audible signal, it advantageously ensures, in particular, enhanced driver attention, which in turn reduces driver fatigue.

[0020] In this preferred configuration, the sound signal output can be activated or deactivated. This allows for personalization based on the driver's needs.

[0021] Another personalized solution that allows for customization based on driver needs is to select the type of sound signal to be output from a pre-defined list of signals / noises. In addition to the shift noise perceived during a "normal shift," the list also includes other selectable signal tones or noises.

[0022] Preferably, the desired number of interruptions during torque output, the interruption duration during torque output, the type of sound signal selected, and the sound signal output activated / deactivated are input using the vehicle's infotainment system. Since the corresponding infotainment system, which centrally controls broadcasting, navigation, multimedia, and comfort and safety functions, is already standard equipment in modern vehicles, these parameters can be input or set effortlessly. Attached Figure Description

[0023] Other advantages and applications of the present invention will become apparent from the following description of the embodiments shown in conjunction with the accompanying drawings.

[0024] in:

[0025] Figure 1 An acceleration graph is shown, which illustrates the vehicle's acceleration in the first operating mode;

[0026] Figure 2 Another acceleration curve is shown, in which the vehicle accelerates according to a second operating mode; and

[0027] Figure 3 Show Figure 2 A magnified view of a portion of the acceleration curve. Detailed Implementation

[0028] Figure 1 and Figure 2 An acceleration curve is shown, generally labeled with reference numeral 10. The acceleration curve shown is labeled with reference numeral 12. (As shown...) Figure 1 and Figure 2 As shown, the speed v of the vehicle is plotted on the x-axis, and the torque M is plotted on the y-axis.

[0029] In this example, the motor vehicle is an electric vehicle without a transmission, meaning that the vehicle does not shift gears when accelerating.

[0030] from Figure 1 It is evident that the acceleration curve 12 of the transmissionless electric vehicle is an uninterrupted curve, that is, a mathematically continuous curve. This uninterrupted curve indicates the first operating mode.

[0031] According to the method described above, motor vehicles can also operate in a second operating mode. This second operating mode... Figure 2 As shown in the image.

[0032] from Figure 2 As can be seen, in the second operating mode, the acceleration curve 12 is a graded or discontinuous curve. In this example, the acceleration curve 12 has n = 4 interruptions. These interruptions are also labeled with reference numeral 14 below. This means that there are four brief drops in torque during acceleration, resulting in traction interruptions that the driver can feel. The traction interruptions, combined with the sound effects caused by the torque changes, have a positive impact on the driver's attention, as they also reduce fatigue effects, which in turn have a positive impact on road traffic safety.

[0033] Furthermore, in this example, in addition to the acoustic effects caused by torque variations, additional sound signals are generated and emitted at each interruption. This further enhances the aforementioned advantage, namely, improved driver attention.

[0034] Preferably, the number of interruptions n, the intensity of torque drop ΔM during an interruption, and the duration of the interruption t are all freely settable. The aforementioned parameters, namely the intensity of torque drop ΔM and the duration of the interruption t, are... Figure 3 As can be seen in the text.

Claims

1. A method for operating a motor vehicle, wherein, The motor vehicle is an electric vehicle without a transmission, which does not shift gears during acceleration. The motor vehicle has a drive unit configured to accelerate the vehicle with continuously variable torque output during acceleration. According to the method, the drive unit can operate in a first operating mode and a second operating mode. In the first operating mode, the motor vehicle accelerates uninterruptedly with the continuously variable torque output, while in the second operating mode, the continuously variable torque output is converted into a stepped torque output, thereby accelerating the motor vehicle intermittently with the stepped torque output. The characteristic feature is that in the second operating mode, an audible signal is generated when the torque output is interrupted, and the type of audible signal to be output can be selected from a pre-given signal / noise list, the audible signal including shift noise mimicking a normal gear shifting process.

2. The method according to claim 1, Its features are, After manipulating the control element, the system performs a switch from the first operating mode to the second operating mode and from the second operating mode back to the first operating mode.

3. The method according to claim 1, Its features are, In the second operating mode, the number of interruptions in the interrupted torque output can be set.

4. The method according to claim 3, Its features are, Input the desired number of interruptions during torque output into the vehicle's infotainment system.

5. The method according to any one of claims 1 to 3, Its features are, In the second operating mode, the interrupted torque output can be configured in terms of the intensity of torque drop during interruption.

6. The method according to claim 5, Its features are, Input the intensity of torque reduction into the vehicle's infotainment system.

7. The method according to any one of claims 1 to 3, Its features are, In the second operating mode, the interrupted torque output can be configured in terms of interruption duration.

8. The method according to claim 6, Its features are, Input the interruption duration during torque output into the vehicle's infotainment system.

9. The method according to claim 1, Its features are, The output of the sound signal can be activated or deactivated.

10. The method according to claim 9, Its features are, Select the sound signal and / or activate / deactivate the sound signal output in the vehicle's infotainment system.

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