Method for operating electric machine of vehicle

Abstract

The invention relates to a method (100) for operating an electric machine (11) of a vehicle (10), in which an electric regenerative signal (101) of the electric machine (11) is influenced.

Description

Technical Field

[0001] The invention relates to a method for operating an electric machine of a vehicle, wherein an electrical regeneration signal of the electric machine is influenced. The invention also relates to an electric machine and a vehicle. Background Art

[0002] Compared to conventional motor vehicles based on internal combustion engines, electric vehicles are characterized by quiet driving behavior. For example, electric vehicles generally have only one gear, which allows acceleration without gear change interruptions. In addition, the electric motor can deliver its full torque from the start without having to reach a high speed first. In contrast, high speeds are required in internal combustion engines in order to be able to deliver more power and torque. This in turn leads to typical noise generation as well as haptically perceptible vibrations and kinematics, which can provide the user of the vehicle with an atmospheric background for the driving experience.

[0003] Compared to conventional vehicles, this type of emotionalization of driving behavior is not available in electric vehicles. In particular, in coasting mode, various typical driving behavior patterns, such as coasting exhaust sounds or jerky internal combustion engine operating behavior, can be clearly perceived in conventional vehicles, thereby achieving greater emotionalization. Summary of the invention

[0004] Against this background, the object of the present invention is to improve a method for operating an electric machine of a vehicle. In particular, it should be possible to design and / or adjust the driving behavior of a vehicle operated by means of an electric machine in order to be able to achieve emotionalization for the vehicle user.

[0005] This object is achieved by a method for operating an electric machine of a vehicle having the features of claim 1, an electric machine having the features of claim 11, and a vehicle having the features of claim 12. The dependent claims relate to advantageous further developments of the invention.

[0006] According to a first aspect, a method for operating an electric machine of a vehicle is specified, wherein during a coasting phase of the vehicle an electrical regeneration signal of the electric machine is influenced by means of an artificially generated electrical signal.

[0007] In this way, the regeneration behavior, regeneration power and / or regeneration phase of the electric machine can be changed and / or modified in order to, for example, influence the drive power transmitted to the drive of the vehicle by means of the electric machine and thus control or modulate the driving behavior of the vehicle. In this way, for example, the haptic perception of the driver or the occupants can be stimulated in order to emotionalize the driving experience.

[0008] For the purposes of the present disclosure, a coasting phase refers to a driving state of the vehicle in which the drive or machine is dragged by the vehicle, i.e. kept in a rotational or driving motion, without the force lock being released. Such a coasting phase is used in electric vehicles and in particular in hybrid vehicles in order to use the energy released in the coasting phase to charge a high-voltage battery. In general, energy is regenerated only with a small regeneration power in the coasting phase. This regeneration power can be artificially increased and / or reduced by means of the artificially generated electrical signal, which can, for example, cause a (particularly enhanced) hysteresis of the vehicle so that it can be perceived by the occupants.

[0009] Vehicles with an electric motor or an electric drive (e.g. a pure electric vehicle or a hybrid vehicle) generally include a regeneration system with which a portion of the kinetic energy can be recovered again during deceleration or during the vehicle's coasting phase (regeneration). During regeneration, the electric drive or the electric motor is operated in generator mode and can thus convert the kinetic energy released during vehicle deceleration into electrical energy. The electrical energy obtained is stored in an electrical energy storage device of the vehicle, such as a battery, and can be used again for the vehicle's drive or for supplying electrical loads (particularly in other driving situations). Regeneration improves the efficiency of the vehicle in particular, since only a relatively small residual portion of the deceleration is converted into heat losses via the service brakes.

[0010] In such a regenerative operation, an electrical regeneration signal is generated in order to output it, for example, to a drive of the vehicle. The regeneration signal can be, for example, an energy signal or a power signal and / or can be generated based on the kinetic power or electrical power that can be recovered or generated. The regeneration signal can be provided and / or transmitted, for example, to the motor, the drive and / or a control unit of the motor and / or the drive.

[0011] In this case, the artificially generated electrical signal is in particular a signal which is superimposed on a regenerative, load-free output signal of the electric machine, in particular in order to achieve an affectation of the driving operation by means of an irregular torque absorption or torque output of the electric machine, in particular in a coasting operation.

[0012] The artificially generated electrical signal may have an origin outside and / or within the motor and may be an energy signal or a power signal. To influence the regeneration signal, the artificially generated electrical signal may be linked or mixed with the regeneration signal to change the regenerated energy flow signal.

[0013] The present invention is now essentially based on the idea of ​​modifying the regenerative, unloaded output signal of the electric machine by means of a further artificially provided signal (i.e. in particular not based on or not only based on a regeneration demand from vehicle operation) (referred to as an artificially generated electrical signal) in such a way that a modified regeneration signal is generated in order in particular to be able to use this modified regeneration signal to physically influence the electric machine, the drive, the vehicle and / or the driving behavior of the vehicle.

[0014] In particular, the regeneration of energy can be influenced by means of the artificially generated electrical signal in such a way that, depending on the determined driver-side or system-side deceleration desire, such a (higher) regeneration power is applied that, for example, temporarily and / or periodically causes a vehicle deceleration that is in particular greater than the vehicle deceleration achieved in a coasting operation (with or without regeneration). The deceleration achieved can even be significantly higher than the deceleration in a normal coasting operation or in a coasting operation with normal regeneration, because the driver assumes or even expects a corresponding driving behavior or braking of the vehicle. In order to identify the driver-side and / or system-side deceleration desire, vehicle data or driving data and / or sensor signals can be evaluated, for example.

[0015] In one embodiment, the artificially generated electrical signal can cause load fluctuations of the electric machine. Load fluctuations here describe the time-dependent change in intensity of the influence on the electric machine or the regenerative operation of the electric machine during the coasting phase. Therefore, load fluctuations occurring during the coasting phase in a motor vehicle with an internal combustion engine, such as coasting exhaust sounds, can be simulated or simulated by means of the modified regeneration signal. In other words, the regeneration can be purposefully modulated by means of the proposed method during the coasting phase to be emotionalized in order to simulate a sporty driving experience similar to that of a conventional vehicle and to make it perceptible to the driver and / or occupants of the vehicle. In particular, the level of the regenerative power of the vehicle and / or the intensity of the deceleration can be predetermined here according to the duration and / or intensity and / or type of at least one determined or to be determined vehicle parameter and / or driving parameter, such as the dynamics of the withdrawal of the actuation of the accelerator pedal.

[0016] In one embodiment, the artificially generated electrical signal can be periodic or have a periodic component. For example, the artificial signal can be designed to rise or fall periodically in order to produce a corresponding haptically perceptible effect in the drive device or in the driving behavior of the vehicle. In this way, various phenomena, in particular phenomena known to vehicle users of vehicles driven by internal combustion engines, can be simulated in order to emotionalize the driving behavior of electrically driven vehicles.

[0017] In one embodiment, the artificially generated electrical signal can influence the frequency of the regeneration signal. By changing the frequency, in particular the time sequence of the individual mechanical effects of the applied regeneration phase can be changed, for example as a function of the vehicle speed, in particular in this respect enabling a harmoniously perceptible driving response to the driver.

[0018] In one embodiment, the artificially generated electrical signal can influence the amplitude of the regeneration signal. By changing the amplitude of the energy flow or power flow, the perceptible intensity or degree of the effect caused by the regeneration (such as load fluctuation) can be changed, so that the driver can achieve emotional driving behavior.

[0019] In one embodiment, the artificially generated electrical signal can be provided by means of an energy source or an energy sink. The energy source can provide energy, in particular by conversion from another energy form. The energy sink can be an electrical consumer that is configured to convert the regenerative energy into another energy form or into another form of electrical energy and thus directly or indirectly use it.

[0020] In one specific embodiment, the artificially generated electrical signal can be provided by means of a control signal or can be a control signal. In this case, the control signal can be provided in particular by means of a control unit of the electric machine or a vehicle control device. By means of the control signal, for example, the electric machine can be caused to generate more energy by means of regeneration, thereby achieving braking of the drive device in order to influence the driving behavior in this way. Thus, for example, various parameters of the vehicle can be taken into account when determining the targeted control of the electric machine and the regeneration behavior associated therewith in order to bring about the desired effect in the driving behavior of the vehicle.

[0021] In one specific embodiment, the regeneration signal can be influenced as a function of the vehicle speed. For example, the intensity or the time sequence of the individual haptically perceptible load fluctuations can be determined and used as a function of the current vehicle speed in order to achieve a simulation of the desired driving behavior that is as realistic as possible.

[0022] In one embodiment, the regeneration signal can be influenced as a function of the actuation gradient of an accelerator pedal of the vehicle. The accelerator pedal can in particular be a foot-operated electronic control unit or an instrument for controlling an acceleration process and / or a braking process. Alternatively or additionally, the brake pressure generated, the brake pedal travel and / or the accelerator pedal angle, the release gradient of the accelerator pedal and / or the actuation gradient of the brake pedal and / or the vehicle deceleration desired by the driver can be taken into account for determining a suitable artificially generated electrical signal to influence the original regeneration signal. In particular, the dynamics of the withdrawal of the actuation of the accelerator pedal can be taken into account when determining and / or generating the artificially generated electrical signal. As a result, not only the position of the accelerator pedal is relevant, but also, in addition, the dynamics of the withdrawal are relevant.

[0023] In one specific embodiment, the regeneration signal can be influenced as a function of the basic regeneration level of the electric machine. The regeneration level is adjustable in order to enable a control of the energy recovery that is adapted to the traffic situation. In order to achieve a haptically perceptible effect, it may be necessary to adapt the artificially generated electrical signal to the currently underlying or currently applied regeneration level.

[0024] According to another aspect, an electric machine for a vehicle is proposed, which comprises a control unit which is configured to influence an electric regeneration signal of the electric machine during a coasting phase of the vehicle by means of an artificially generated electric signal. The advantages of the proposed electric machine correspond substantially to the advantages of the proposed method described in detail above, and therefore are not repeated here.

[0025] According to a further aspect, a vehicle is provided having an electric machine, wherein the electric machine is provided for carrying out the method described herein and / or is designed in the manner described herein. The invention is suitable in particular for hybrid vehicles and electric vehicles, but is not restricted to this field of application.

[0026] Further features, advantages and application possibilities of the invention result from the following description in conjunction with the drawings.In general, the features of the various exemplary aspects and / or embodiments described herein can be combined with one another, as long as this is not explicitly excluded in the context of the present disclosure.

[0027] In the following part of the specification, reference is made to the drawings shown, which are shown to illustrate specific aspects and embodiments of the present invention. It should be understood that other aspects may be used, and that structural or logical changes to the depicted embodiments are feasible without departing from the scope of the present invention. Therefore, the following description of the drawings should not be understood as limiting. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A schematic diagram shows a flow chart of a method according to the present invention for operating an electric machine of a vehicle.

[0029] Figure 2 An exemplary embodiment of a vehicle according to the invention is shown in a schematic diagram. DETAILED DESCRIPTION

[0030] Figure 1 A flow chart of an exemplary embodiment of a method 100 according to the present invention for operating an electric machine of a vehicle is shown in a schematic diagram.

[0031] The flow chart begins with a first step 101 , in which an especially load-free electrical regeneration signal of the electric machine is generated during a coasting phase of the vehicle.

[0032] In a second step 102, an artificial electrical signal is determined as a function of a determined or to be determined vehicle speed 201, a determined or to be determined actuation gradient 202 of an accelerator pedal of the vehicle and a determined or to be determined basic regeneration level 203. This can be done, for example, by means of a control unit of the electric machine.

[0033] The artificial electrical signal is generated in step 103. Here, an energy sink in the form of an additional electrical consumer can be controlled in such a way that it requires a higher regenerative power from the electric machine. Here, the artificially generated electrical signal can be periodic or have a periodic component.

[0034] In step 104, the electrical regeneration signal 101 is influenced by means of the artificially generated electrical signal 103 in order to generate a modified regeneration signal. Optionally, the regeneration signal from step 104 can also be incorporated as feedback into the calculation in step 102, and the artificial electrical signal determined in this way can be modified again. In this way, the regeneration operation of the electric machine can be changed as a function of at least one operating parameter of the vehicle in order to cause a load fluctuation of the electric machine.

[0035] Figure 2 A vehicle 10 according to the invention is shown, which has an electric machine 11, a high-voltage battery 12 for storing regenerative energy, a drive device 14, a speed sensor 15 and a pedal sensor 16. The pedal sensor 16 can determine an accelerator pedal gradient that is influenced by actuation of an accelerator pedal of the vehicle 10. The electric machine in turn comprises a control unit 13 and is configured to generate an electrical regeneration signal during a coasting phase of the vehicle 10, in particular as a function of the regeneration power.

[0036] Depending on the detected accelerator pedal gradient and the detected vehicle speed, the control unit 13 can generate an artificially generated electrical signal in order to influence the electrical regeneration signal of the electric machine 11 in order to thereby, for example, change the power output to the drive device 14. In this way, for example, the time profile of the regeneration power can be adjusted in order to generate load fluctuations on the electric machine 11. Reference numerals list

[0037] 10 Vehicles

[0038] 11 Motor

[0039] 12 high voltage batteries

[0040] 13Control Unit

[0041] 14 Drive device

[0042] 15 Speed ​​sensor

[0043] 16 pedal sensor

[0044] 100 Methods

[0045] Steps 101 to 104

[0046] 201 to 203 Vehicle parameters or driving parameters

Claims

1. A method (100) for operating an electric machine (11) of a vehicle (10), wherein: During a coasting phase of the vehicle, an electrical regeneration signal (101) of an electric machine (11) is influenced by means of an artificially generated electrical signal (104).

2. The method (100) according to the preceding claim, wherein: The artificially generated electrical signal causes load fluctuations of the motor (11).

3. The method (100) according to any one of the preceding claims, wherein: The artificially generated electrical signal is periodic.

4. The method (100) according to any one of the preceding claims, wherein: The artificially generated electrical signal affects the frequency of the regenerated signal.

5. The method (100) according to any one of the preceding claims, wherein: The artificially generated electrical signal affects the amplitude of the regenerated signal.

6. The method (100) according to any one of the preceding claims, wherein: The artificially generated electrical signal is provided by means of an energy source or an energy sink.

7. The method (100) according to any one of the preceding claims, wherein: The artificially generated electrical signal is provided by means of a control signal.

8. The method (100) according to any one of the preceding claims, wherein: The regeneration signal is influenced according to vehicle speed (201).

9. The method (100) according to any one of the preceding claims, wherein: The regeneration signal is influenced as a function of an actuation gradient (203) of an accelerator pedal (16) of the vehicle (10).

10. The method (100) according to any one of the preceding claims, wherein: The regeneration signal is influenced according to a basic regeneration level (203) of the electric machine (11).

11. An electric machine (11) for a vehicle (10), comprising a control unit (13) which is configured to influence (104) an electric regeneration signal of the electric machine during a coasting phase of the vehicle by means of an artificially generated electric signal.

12. A vehicle (10) having an electric machine (11), wherein: The electric machine (10) is provided for carrying out a method (100) according to any one of claims 1 to 10 and / or the electric machine is designed according to claim 11.

Images