WO2023117287A1

WO2023117287A1 - Drive device for a vehicle and method for operating a drive device

Info

Publication number: WO2023117287A1
Application number: PCT/EP2022/083082
Authority: WO
Inventors: Florian Schlumpp; Paul Oborowski
Original assignee: Robert Bosch Gmbh
Priority date: 2021-12-22
Filing date: 2022-11-24
Publication date: 2023-06-29
Also published as: DE102021214860A1

Abstract

The present invention relates to a drive device (10) for a vehicle (F), comprising a first electric axle (E1) having a first electric machine (EM1), a second electric axle (E2) having a second electric machine (EM2), and a control device (SE) which is connected to the first electric machine (EM1) and to the second electric machine (EM2) and is designed to control the operation of the first electric machine (EM1) and of the second electric machine (EM2) according to a predetermined operating scenario, for the purpose of distributing a first torque (M1) from the first electric axle (E1) and the second electric axle (E2), in such a way that a temperature and/or a degree of efficiency at the first electric axle (E1) and/or at the second electric axle (E2) reaches a predetermined level.

Description

title

Drive device for a vehicle and method for operating a drive device

The present invention relates to a drive device for a vehicle and a method for operating a drive device.

State of the art

When operating battery-electric vehicles, which have two driven axles, an operating strategy can be implemented in the vehicle control unit (Vehicle Control Unit, VCU), which can regulate the torque distribution between the front and rear axles.

In order to extend the range of the vehicle, the VCU can control the torque distribution to optimize efficiency. This can result in an operating state in which the electric drives of an axis can be switched off completely. The driver's desired torque can be applied by the axle that is still active. This working point shift can result in better overall efficiency and increase the range of the vehicle. Torque distribution can lead to different loads on the two driven axles, which can cause their components to heat up differently. If the temperature of a component of an axle reaches a certain range, the torque distribution can be changed or the desired drive can be limited, which should lead to a reduction in the thermal load on the axle. If the VCU switches off an electrically driven axle, there may still be a drag loss on the switched off axle. The drag loss can be compensated for by the axle that is still driven. In general, drag losses can occur in the transmission if the oil in the transmission is not at the optimum operating temperature. It would be desirable to take the oil temperature into account in the operating strategy for optimum efficiency.

WO 2011/128024 A1 describes a method for operating a motor vehicle.

Disclosure of Invention

The present invention provides a drive device for a vehicle according to claim 1 and a method of operating a drive device according to claim 8.

Preferred developments are the subject of the dependent claims.

Advantages of the Invention

The idea on which the present invention is based is to specify a drive device for a vehicle and a method for operating a drive device, wherein control of various drive axles in a vehicle can be improved and/or efficiency of the drive can be increased.

According to the invention, the drive device for a vehicle comprises a first electric axle with a first electric machine; a second electric axle with a second electric machine; and a control device, which is connected to the first electrical machine and to the second electrical machine and is set up to operate the first electrical machine and the second electrical machine depending on a predetermined operating scenario for a distribution of a first to control torque from the first electric axis and a second torque from the second electric axis such that a temperature and/or an efficiency at the first electric axis and/or at the second electric axis reaches a predetermined level.

The control device can be a control device provided in particular for one or both electrical machines, or it can be a control device of another vehicle system, for example a driving stability system (ESP).

The predetermined operating scenario can relate to a drive which uses both axles equally or which prefers one of the two axles for driving, for example on inclines. However, the predetermined operating scenario can also relate to commissioning of the drive and its components, for example a torque and a load on one of the two drives and axles can be increased or reduced compared to the other drive (axle) in order to bring the components of the affected axle up to operating temperature more quickly to get. The predetermined level can relate to a value range of an associated parameter, which this parameter can assume in the predetermined operating scenario.

According to a preferred embodiment of the drive device, the first electric axle is a front axle and the second electric axle is a rear axle of the vehicle.

According to a preferred embodiment of the drive device, this comprises a temperature sensor and/or a torque sensor in the first electrical axis and/or in the second electrical axis and from which a temperature of a transmission and/or an oil and/or an electronic system and/or a coolant can be determined in the first electrical axis and/or in the second electrical axis and/or a first torque can be determined by the first electrical axis and/or a second torque can be determined by the second electrical axis.

The sensors can advantageously relate to the actual state of the drive

Torque, speed, temperature of components or coolant and/or other parameters are checked and adjusted to a desired specification or to a desired level, advantageously by controlling the respective drive.

According to a preferred embodiment of the drive device, the control device is set up to change, according to the predetermined operating scenario, a first torque from the first electric axis and/or a second torque from the second electric axis in such a way that a specific change in a temperature of a transmission and/or of an oil and/or electronics and/or a coolant in the first electric axis and/or in the second electric axis is achieved and thereby a first efficiency of the first electric axis and/or a second efficiency of the second electric axis is increased.

Through targeted operation, the respective axis and its drive can be brought to a specific operating state.

According to a preferred embodiment of the drive device, the control device is set up to increase a transmission temperature and/or an oil temperature in the first electrical axle and/or in the second electrical axle through the predetermined operating scenario and thereby reduce a viscosity of the transmission oil.

A reduced viscosity can advantageously increase the efficiency of the affected drive.

According to a preferred embodiment of the drive device, the control device is set up to use the predetermined operating scenario to apply a torque distribution between the first electric axle and/or the second electric axle in order to thereby increase the overall efficiency of the drive device on the vehicle and to meet a predetermined specification. The torque distribution can relate to setting up or generating a specific first torque and a specific second torque according to a specific specification.

According to a preferred embodiment of the drive device, the control device is set up to influence the torque distribution through the predetermined operating scenario, taking into account a temperature model of the transmission of the first electric axis and/or the second electric axis, so that the transmission efficiency of the axis prioritized for the drive increases .

The torque distribution between the first and second axles, for example between the front and rear axles, can be changed according to the invention in such a way that the driven axles can achieve greater efficiency by adjusting the temperature of at least one of their components. Furthermore, waste heat from structurally (at least thermally interacting) adjacent components in the vehicle can be used, which, based on the vehicle design and component positioning, can have a high heat transfer to the relevant components (transmission, electric machine, inverter, coolant).

A higher degree of efficiency can also be achieved, for example, by adapting the temperature of the transmission and/or the transmission oil temperature. This temperature adjustment can reduce the viscosity of the transmission oil, which can lead to a reduction in power loss.

Knowing and specifying the operating scenario and the associated operating strategy, the efficiency of the first and/or second axis can be increased in a targeted manner, advantageously that axis which can generally be used more frequently under this operating scenario. In this case, the drag losses of the deactivated axle or the axle reduced in operation can be minimized in order to reduce the required drive power. Thereby can reducing operation, reducing speed, torque, oil temperature or other.

The overall efficiency of the drive (powertrains) can be increased in a targeted manner according to a specification using forward-looking, predictive information (e.g. for the near future of operation).

In the (driving) operating points with a high power requirement, both drive machines can be used, whereby the efficiency of both or at least one drive machine can be optimized. For this purpose, a temperature adjustment of the axles can be coupled to one another via the torque distribution, for example by first shifting the torque distribution to the drive machine that is to reach a higher temperature and is to be operated with high efficiency by reducing the viscosity of the transmission oil. The overall efficiency of the vehicle can be optimized and set using a weighting function for generating the first torque and the second torque relative to one another, in which case the temperatures in both drives are as high as possible and result in a low viscosity of the transmission oil in both drives.

By controlling the drives (power, torque), the cooling capacity of the drive components on the corresponding axis can be actively influenced in order to support reaching, maintaining or achieving the desired temperature.

An optimization can intend that the efficiency can be optimized over the entire journey. It can therefore be expedient to use a torque distribution at the beginning of a journey that does not result in minimal energy consumption in order to ensure that one or both drives heat up as quickly as possible. The initial increased consumption compared to the instantaneous operating strategy can then be compensated for by the fact that the drive or drives reach a temperature earlier at which the efficiency of at least one drive can be optimal or at least improved. The temperature of individual drive components in one or both drives/axles can be adjusted in a targeted manner in order to increase the overall efficiency of the system. The range of the vehicle can be extended, as can a reduction in the energy costs per km and/or a reduction in the cooling components required (increased efficiency leads to lower power loss).

According to the invention, in a method for operating a drive device, a drive device according to the invention is provided; determining a temperature of a transmission and/or an oil and/or an electronics and/or a coolant in the first electric axis and/or in the second electric axis and/or a first torque of the first electric axis and/or a second torque from the second electrical axis; controlling an operation of the first electric machine and the second electric machine by the control device depending on a predetermined operating scenario for a distribution of a first torque from the first electric axis and a second torque from the second electric axis such that a temperature and/or an efficiency at the first electrical axis and/or at the second electrical axis reaches a predetermined level.

The predetermined operating scenario can for a desired operation specifications for a temperature of a transmission and / or an oil and / or electronics and / or a coolant in the first electric axis and / or in the second electric axis and / or a first torque from the first electrical axis and/or a second torque from the second electrical axis.

According to a preferred embodiment of the method, the predetermined operating scenario is specified by a user when producing the drive device in the control device or before or during operation of the drive device by a user or by a control system via a communication device or via a User interface transmitted to the control device, or created by the control device itself based on environmental data of the vehicle and / or driving data of the vehicle.

The environmental data can relate to the course of the road, environmental conditions (weather or other factors), objects in the area, road surface or other surfaces or the like and can be determined with a navigation device or via sensors or a weather or traffic report.

The user interface can be an input device in the vehicle, or it can be a mobile phone or computer.

According to a preferred embodiment of the method, an expected driving course of the vehicle is recognized or predetermined and an associated control of the first torque on the first electric axle and the second torque on the second electric axle takes place depending on a prioritization of the first electric axle or the second electric axle for the recognized or predetermined driving course to be expected.

The associated control may correspond to a desire or relate to optimization in terms of time used or in terms of efficiency or in terms of heating of the components.

The drive device can also be characterized by the features mentioned in connection with the method and its advantages, and vice versa.

Further features and advantages of embodiments of the invention result from the following description with reference to the accompanying drawings.

Brief description of the drawings The present invention is explained in more detail below with reference to the exemplary embodiments given in the schematic figures of the drawing.

Show it:

1 shows a schematic representation of a drive device according to an exemplary embodiment of the present invention;

FIG. 2 shows a schematic representation of a course of a viscosity as a function of an oil temperature; FIG.

3 shows a schematic representation of a distribution of a torque in the method for operating a drive device according to an embodiment of the present invention; and

4 shows a block diagram of method steps of the method for operating a drive device according to an exemplary embodiment of the present invention.

In the figures, the same reference symbols denote the same elements or elements with the same function.

1 shows a schematic representation of a drive device according to an embodiment of the present invention.

The drive device 10 for a vehicle F includes a first electric axle El with a first electric machine EMI; a second electric axis E2 with a second electric machine EM2; and a control device SE, which is connected to the first electrical machine EMI and to the second electrical machine EM2, and is set up to operate the first electrical machine EMI and the second electrical machine EM2 depending on a predetermined operating scenario for a distribution of a to control first torque from the first electrical axis El and a second torque from the second electrical axis such that a temperature and / or Efficiency on the first electric axis and / or on the second electric axis reaches a predetermined level. The first electric axis El can represent a front axle and the second electric axis E2 can represent a rear axle of the vehicle.

FIG. 2 shows a schematic representation of a course of a viscosity as a function of an oil temperature.

The viscosity V as a function of temperature is shown for two different types of oil, for example on the two different drive axles or for the same drive axle.

A torque distribution can be controlled from a temperature-efficiency characteristic of the installed drive components, which can be used to increase the overall efficiency of the system, which can be shown from the example in FIG. 2 and the transmission oil temperature shown there. According to FIG. 2, with common transmission oil types, the viscosity V of the oil can change, in particular decrease, at a higher temperature, which can be different for different oil types OL1 and OL2. This makes it possible that an increase in the efficiency of the transmission can be achieved with the generated temperature. This can result in a relationship between the transmission efficiency and the transmission temperature. In turn, the transmission temperature is based on the drive power. A higher drive power of an axle thus also leads to a higher gearbox temperature. According to the invention, a (control) function can then be developed and implemented in the control device (Fig. 1), which, taking into account a temperature model of the transmission, can change the torque distribution on the first and second axes in such a way that the transmission efficiency of the prioritized axis can be improved , which can ultimately lead to a higher efficiency of the entire drive system.

Relevant temperatures (transmission oil temperature or temperatures of other components that correlate with the oil temperature, eg transmission surface) can be measured and/or checked. In case that If one of the temperatures is too low, i.e. lower than a predetermined value (e.g. if the transmission is too cold), a heating mode (e.g. by selecting the torque on the axle) can be activated. Furthermore, the course of the journey can be predicted, in which case it is determined (a course of the journey can be at least approximately predicted from the control device and other vehicle assistance components or computer) that an axle is likely to be used only little in the further course of the route, for example less than a predetermined power or Duration, a heating mode can be generated and activated by a corresponding drive power.

FIG. 3 shows a schematic representation of a distribution of a torque in the method for operating a drive device according to an exemplary embodiment of the present invention.

The illustration shows an operating strategy based on the prior art using the dashed lines (K1 and K2) and an operating strategy according to the invention using the solid lines (K3 and K4).

In the case of the operating strategy according to the prior art, a torque distribution (K2), represented as a ratio of the drive power of the drives M1/M2, is selected in which one drive is switched off completely and is dragged along. The resulting overall efficiency (WG der Kl) of all drives is low at the beginning of the journey due to the temperature dependency and increases with increasing temperature t (reduction in viscosity). The operating strategy according to the invention, on the other hand, provides for the drive power to be distributed to all drives at the beginning of the journey in the warm-up phase (AM—warm-up mode) in such a way that the drives heat up as quickly as possible (K4 in the AM area). As soon as the drives have reached a temperature that is optimal for efficiency, the operating strategy switches to energy efficiency mode (EFM) and optimizes the torque distribution for the lowest possible energy consumption (K4 in the EM area). The recognizable advantage of the operating strategy of the invention is that the optimal operating temperature of the drives (K3) is reached earlier than after the warm-up phase (AM). Operating strategy according to the state of the art (Kl). The faster heating up results in a reduction in the energy consumption of the vehicle, which also applies if the operating strategy according to the prior art is used again in the further course of the journey.

Kl and K3 are the efficiency and K2 and K4 are a torque distribution according to M1/M2.

FIG. 4 shows a block diagram of method steps of the method for operating a drive device according to an exemplary embodiment of the present invention.

In the method for operating a drive device, a drive device according to the invention is provided S1; determining S2 a temperature of a transmission and/or an oil and/or an electronic system and/or a coolant in the first electric axis and/or in the second electric axis and/or a first torque of the first electric axis and/or a second torque from the second electrical axis; controlling S3 operation of the first electrical machine and the second electrical machine by the control device depending on a predetermined operating scenario for a distribution of a first torque from the first electrical axle and the second electrical axle such that a temperature and/or an efficiency a predetermined level is reached on the first electric axis and/or on the second electric axis.

Although the present invention has been fully described above with reference to the preferred exemplary embodiment, it is not restricted thereto but can be modified in a variety of ways.

Claims

Expectations

1. Drive device (10) for a vehicle (F), comprising:

- A first electrical axis (El) with a first electrical machine (EMI);

- A second electric axis (E2) with a second electric machine (EM2); and

- A control device (SE), which is connected to the first electrical machine (EMI) and to the second electrical machine (EM2), and is set up to operate the first electrical machine (EMI) and the second electrical machine (EM2) depending on a predetermined operating scenario for a distribution of a first torque (Ml) from the first electrical axis (El) and a second torque (M2) from the second electrical axis (E2) to control such that a temperature and / or an efficiency reaches a predetermined level on the first electrical axis (El) and/or on the second electrical axis (E2).

2. Drive device (10) according to claim 1, in which the first electric axis (El) is a front axle and the second electric axis (E2) is a rear axle of the vehicle.

3. Drive device (10) according to claim 1 or 2, which comprises a temperature sensor and / or a torque sensor in the first electrical axis (El) and / or in the second electrical axis (E2) and of which a temperature of a transmission and / or an oil and / or electronics and / or a coolant in the first electrical axis (El) and / or in the second electrical axis (E2) can be determined and / or a first torque from the first electrical axis (El) and / or a second torque can be determined by the second electrical axis (E2).

4. Drive device (10) according to one of claims 1 to 3, in which the control device (SE) is set up to, according to the predetermined operating scenario, a first torque from the first electric axis (El) and / or a second torque from the second electric Axis (E2) to change such that a certain change in temperature of a transmission and / or oil and / or electronics and / or a coolant in the first electrical axis (El) and / or in the second electrical axis (E2) is achieved and thereby a first efficiency of the first electrical axis (El) and / or a second efficiency of the second electrical axis (E2) is increased.

5. Drive device (10) according to Claim 4, in which the control device (SE) is set up to use the predetermined operating scenario to determine a transmission temperature and/or an oil temperature in the first electric axis (El) and/or in the second electric axis (E2 ) and thereby reduce a viscosity of the transmission oil.

6. Drive device (10) according to claim 4 or 5, in which the control device (SE) is set up to apply a torque distribution between the first electric axis (El) and/or the second electric axis (E2) by the predetermined operating scenario in order to thereby to increase an overall efficiency of the drive device on the vehicle and to correspond to a predetermined specification.

7. Drive device (10) according to one of claims 4 to 6, in which the control device (SE) is set up to, through the predetermined operating scenario, taking into account a temperature model of the transmission of the first electric axis (El) and / or the second electric axis ( E2) to influence the torque distribution in such a way that the transmission efficiency of the axis prioritized for the drive increases.

8. A method for operating a drive device (10), comprising the steps:

- Providing (Sl) a drive device (10) according to any one of claims 1 to 7;

- Determining (S2) a temperature of a transmission and / or an oil and / or electronics and / or a coolant in the first electric axis (El) and / or in the second electric axis (E2) and / or a first torque of the first electric axis (El) and/or a second torque from the second electric axis (E2);

- Controlling (S3) an operation of the first electrical machine (EMI) and the second electrical machine (EM2) by the control device (SE) depending on a predetermined operating scenario for a distribution of a first torque - 15 -

(Ml) from the first electric axis (El) and a second torque from the second electric axis (E2) such that a temperature and/or an efficiency on the first electric axis (El) and/or on the second electric axis ( E2) reaches a predetermined level.

9. The method according to claim 8, in which the predetermined operating scenario is specified by a user when the drive device is manufactured in the control device or is transmitted to the control device by a user or by a control system via a communication device or via a user interface before or during operation of the drive device is, or is created by the control device based on environmental data of the vehicle and / or driving data of the vehicle itself.

10. The method according to claim 8 or 9, in which an expected driving course of the vehicle is recognized or predetermined and an associated control of the first torque on the first electric axle (E1) and the second torque on the second electric axle (E2) takes place in Dependence on a prioritization of the first electric axis (E1) or the second electric axis (E2) for the recognized or predetermined driving course to be expected.