A drive system for an at least in part electrically operated motor vehicle as well as a method for operating a drive system

Abstract

A drive system 12 for an at least in part electrically operated motor vehicle (10), wherein the drive system comprises at least a first electric drive unit 20, which is connected to a first axle (16)

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the field of automobiles. More specifically, the present invention relates to a drive system for an in part electrically operated motor vehicle as well as to a corresponding method for operating a drive system. BACKGROUND INFORMATION

[0002] High performance electric vehicles may include two motors per axle. With two motors per axle, the drive system can increase output torque / power and implement electric torque vectoring. However, uncontrolled electric torque vectoring may involve a high risk and may cause a motor vehicle accident. Therefore, a high level and high speed in diagnostics is required. SUMMARY OF THE INVENTION

[0003] It is an object of the present invention to provide a drive system as well as a corresponding method for operating a drive system, by which the safety of an in part electrically operated motor vehicle is increased.

[0004] This object is solved by a drive system as well as a corresponding method for operating a drive system according to the independent claims. Advantageous embodiments are presented in the dependent claims.

[0005] One aspect of the present invention relates to a drive system for an at least in part electrically operated motor vehicle, wherein the drive system includes at least a first electric drive unit, which is connected to a first axle of the motor vehicle, and a second electric drive unit, which is connected to the first axle.

[0006] According to the embodiment, a first electronic computing device of the first electric drive unit may be connected via a communication link of the drive system to a second electronic computing device of the second electric drive unit, wherein the first electronic computing device may be configured for monitoring the second electronic computing device via the communication link and vice versa.

[0007] Therefore, an improved level in high speed diagnostic between the electric drive units, which are arranged at the same first axle, may be provided. For example, a rear left and a rear right electric drive unit or a front left and a front right electric drive unit may be configured as the first electric drive unit and the second electric drive unit.

[0008] Therefore, in particular in contrast to a design with one motor control unit for a dual motor drive, by the present invention a simple setup is provided.

[0009] Specifically, the motor vehicle may have a rear left motor electric drive unit and a rear right motor electric drive unit. Both electronic computing devices, which may also be regarded as a controller, are arranged very close together and at the same electric potential and to common ground. An assigned high speed communication bus is provided to monitor the other electric drive unit. The high speed communication bus provides a high level diagnostic, high speed diagnostic, and high speed reaction. Furthermore, a redundant shutdown command between the rear left electric drive unit and the rear right electric drive unit with a digital input / output may be provided. This increases reliability of fault reaction and decreases fault reaction time.

[0010] According to an embodiment, the first electric drive unit and the second electric drive unit are connected to the same electric potential and to common ground.

[0011] In another embodiment, the first electronic computing device may be configured for performing a high level diagnostic and / or a high speed diagnostic and / or a high speed reaction of the second electronic computing device and vice versa.

[0012] In another embodiment, the communication link may be a serial peripheral interface or a CAN-Bus connection or an inter-integrated circuit connection.

[0013] In another embodiment, the first electric drive unit and / or the second electric drive unit includes an axial flux motor.

[0014] In another embodiment, depending on the monitoring a torque vectoring of the first electric drive unit and / or the second electric drive unit may be performed.

[0015] In another embodiment, additionally a shutdown link between the first electronic computing device and the second electronic computing device may be provided.

[0016] A further aspect of the present invention relates to a motor vehicle including the drive system according to the preceding aspect. The motor vehicle may be configured as an at least in part electrically operated motor vehicle or a fully electrically operated motor vehicle.

[0017] Furthermore, the present invention relates to a method for operating a drive system of an at least in part electrically operated motor vehicle according to the preceding aspect, wherein a first electronic computing device of a first electric drive unit of the drive system monitors a second electronic computing device of a second electric drive unit of the drive system via a communication link between the first electronic computing device and the second electronic computing device and / or vice versa.

[0018] The electronic computing devices may include electronic means, for example, processors, circuits, for example integrated circuits, and further electronic means for performing the method.

[0019] Advantageous forms of configurations of the drive system are to be regarded as advantageous forms of the method.

[0020] Further advantages, features, and details of the present invention derive from the following description of a preferred embodiment as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figure and / or shown in the figure alone can be employed not only in the respectively indicated combination but also in any other combination or taken alone without leaving the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The novel features and characteristic of the present disclosure are set forth in the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and together with the description, serve to explain the disclosed principles. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and / or methods in accordance with embodiments of the present subject matter are now described below, by way of example only, and with reference to the accompanying figures.

[0022] The drawings show in:

[0023] Fig. 1 a schematic top view of an embodiment of a motor vehicle including an embodiment of a drive system;

[0024] Fig. 2 a schematic block diagram according to an embodiment of a drive system;

[0025] Fig. 3 another schematic block diagram according to an embodiment of the drive system; and

[0026] Fig. 4 another schematic block diagram according to an embodiment of the drive system.

[0027] In the figures the same elements or elements having the same function are indicated by the same reference signs. DETAILED DESCRIPTION

[0028] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0029] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawing and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0030] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion so that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus preceded by “comprises” or “comprise” does not or do not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

[0031] In the following detailed description of the embodiment of the present disclosure, reference is made to the accompanying drawing that forms part hereof, and in which is shown by way of illustration a specific embodiment in which the disclosure may be practiced. This embodiment is described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0032] Fig. 1 shows a schematic top view according to an embodiment of a motor vehicle 10. The motor vehicle 10 includes a drive system 12, 14. According to the shown embodiment, a first drive system 12 for a first axle 16 is shown and a second drive system 14 for a second axle 18 is shown. In some embodiments, the first axle 16 may be a rear axle, and the second axle 18 may be a front axle of the motor vehicle 10.

[0033] Subsequently, the present invention is explained by means of the first drive system 12. It is obvious for a person skilled in the art that the same explanation is relevant for the second drive system 14.

[0034] The first drive system 12 includes at least a first electric drive unit 20 which is connected to the first axle 16 of the motor vehicle 10 and a second electric drive unit 22, which is also connected to the first axle 16. The second drive system 14 may include a third electric drive unit 24 and a fourth electric drive unit 26, which are connected to the second axle 18.

[0035] Fig. 2 shows a schematic block diagram according to an embodiment of the drive system 12, 14. According to the shown embodiment, the first electric drive unit 20 may include a first electronic computing device 28, and the second electric drive unit 22 may include a second electronic computing device 30. The first electronic computing device 28 may include a first printed circuit board (PCB) 32 and the second electronic computing device 30 may include a second PCB 34. According to the shown embodiment, a communication link 36 is provided between the first PCB 32 and the second PCB 34. For example, the communication link 36 may be a serial peripheral interface or a CAN-bus connection or an inter-integrated circuit connection.

[0036] Furthermore, Fig. 2 shows that the first electric drive unit 20 and the second electric drive unit 22 are connected to the same electric potential and to common ground 38.

[0037] Furthermore, a shutdown link 40 between the first electronic computing device 28 and the second electronic computing device 30 is provided.

[0038] In particular, the figures show that high-performance electric motor vehicles 10, which may be at least in part electrically operated or fully electrically operated, may comprise for example two electric drive units 20, 22 per first axle 16. With the two motors per first axle 16, the motor vehicle 10 may increase the output torque / power and implement electric torque vectoring. But uncontrolled electric torque vectoring is a high risk and may cause, for example, an accident wherein it needs to be monitored in a high level and high speed diagnostic within the same motors at the same first axle 16. If one motor control unit controls both motors at the same time, a motor driver may perform high level and high speed diagnostic. It will increase complexity of the hardware development and the software development.

[0039] Therefore, according to the invention, the electronic computing devices 28, 30 are arranged very close together at the same electric potential with common ground. An assigned high speed communication bus, for example a CAN-connection, a serial peripheral interface, or an inter-integrated circuit, is provided to monitor the other electric drive unit 20, 22. It provides a high level diagnostic, high speed diagnostic, and a high speed reaction. Furthermore, a redundant shutdown command between the first electric drive unit 20 and the second electric drive unit 22 with a digital input / output is provided.

[0040] Figs. 3A and 3B shows another schematic block diagram according to an embodiment of the drive system 12, 14. In particular the communication module for a communication of the two electronic computing devices 28, 30 is shown, wherein one electronic computing device 28, 30 is configured as a master and one as a slave.

[0041] Now the abbreviations used in Figs. 3A and 3B are explained in more detail: SPI - Synchronous Peripheral Interface MCU - microcontroller unit MCUE^ - First / Second Emergency Stop Input signal to MCU MCU_EST_OUT1 / MCU_EST_OUT2 - First / Second Emergency Stop Output signal from MCU HWCNTLGD - Hardware control unit for Gate Driver SBC SS1 / SBC SS2 - First / Second Emergency Stop Output signal from SBC ( System Base Chip, Watchdog Device, MCU monitoring Device) MCU_OUT_FB / MCU_OUT_FB2 - First / Second Emergency Stop Output feedback signal to MCU

[0042] Fig. 3B shows another embodiment of the drive system 12, 14. The communication for the drive system 12, 14 may be simplified and may be used for a digital shutdown. The digital shutdown may occur during a loss of the communication with the communication link 36, loss of functionality of the electric drive unit 20, 22, loss of functionality the drive system 12,14 or another condition. During these events, the digital input interface between the electronic computing device 28, 30 may enable the digital shutdown. For example, the digital shutdown may be initiated using the shutdown link 40.

[0043] Fig. 4 shows another schematic block diagram according to an embodiment of the drive system 10. In particular the communication link 36 between the two electronic computing devices 28, 30 is shown, wherein one electronic computing device 28, 30 is configured as a master and one as a slave.

[0044] The communication link 36 may include signals such as a synchronous peripheral interface clock output, a synchronous peripheral interface clock input, a master SPI data output, a slave SPI data output, a synchronous peripheral interface master slave select output, a synchronous peripheral interface master slave select input, or other comparable signals. The signals may be used to transmit and receive data between the electronic computing device 28, 30 for motor control.

[0045] For example, each electronic computing device 28, 30 may update 3 Key value every motor control task (ex. 100usec) or 1msec: Motor Output Torque, Operating Speed with Scale and Operating Status : Torque 1 = int ( Motor Output Torque * 10 ) + Offset valuel; Torque 2 = int ( Motor Output Torque * 5 ) + Offset value2 Operating Speedl = int( Operating Speed *10 ) + Offset Speedl; Operating Speed2 = int( Operating Speed *5 ) + Offset Speed2; Operating Statusl = ( Normal, idle and Fault) Operating Status2 = ( Normal, idle and Fault) Reference Signs motor vehicle first drive system second drive system first axle second axle first electric drive unit second electric drive unit third electric drive unit fourth electric drive unit first electronic computing device second electronic computing device first printed circuit board (PCB) second PCB communication link ground shutdown link

Claims

1. A drive system (12) for an at least in part electrically operated motor vehicle (10), wherein the drive system (10) comprises at least a first electric drive unit (20), which is connected to a first axle (16) of the motor vehicle (10), and a second electric drive unit (22), which is connected to the first axle (16), characterized in thata first electronic computing device (28) of the first electric drive unit (20) is connected via a communication link (36) of the drive system (12) to a second electronic computing device (30) of the second electric drive unit (22), wherein the first electronic computing device (28) is configured for monitoring the second electronic computing device (30) via the communication link (36) and vice versa.

2. The drive system (12) according to claim 1, characterized in thatthe first electric drive unit (20) and the second electric drive unit (22) are connected to the same electric potential and to common ground (38).

3. The drive system (12) according to claim 1 or 2, characterized in thatthe first electronic computing device (28) is configured for performing a high level diagnostic and / or a high speed diagnostic and / or a high speed reaction of the second electronic computing device (30) and vice versa.

4. The drive system (12) according to any one of claims 1 to 3, characterized in thatthe communication link (36) is a serial peripheral interface or a CAN-Bus connection or an inter-integrated circuit connection.

5. The drive system (12) according to any one of claims 1 to 4, characterized in thatthe first electric drive unit (20) and / or the second electric drive unit (22) comprises an axial flux motor.

6. The drive system (12) according to any one of claims 1 to 5, characterized in thatdepending on the monitoring a torque vectoring of the first electric drive unit (20) and / or the second electric drive unit (22) is performed.

7. The drive system (12) according to any one of claims 1 to 6,characterized in thatadditionally a shutdown link (40) between the first electronic computing device (28) and the second electronic computing device (30) is provided.

8. A method for operating a drive system (12) of an at least in part electrically operated motor vehicle (10) according to any one of claims 1 to 6, wherein a first electronic computing device (28) of a first electric drive unit (20) of the drive system (12) monitors a second electronic computing device (30) of a second electric drive unit (22) of the drive system (12) via the communication link (36) between the first electronic computing device (28) and the second electronic computing device (30) and / or vice versa.

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