METHOD FOR HEATING A DRIVETRAIN AND / OR SUBSTITUTION OF A VEHICLE AND CONTROL ARRANGEMENT FOR EXECUTING THE METHOD

Abstract

Method, performed by a control arrangement, for heating a drivetrain (10) and / or a subsystem of a vehicle (1). The vehicle (1) comprises an electric machine (12) configured to supply motive power to one or more drive wheels (4, 5) of the vehicle and / or to drive a power take-off (PTO) load. The method comprises, when the electric machine (12) is disconnected from the one or more drive wheels (4, 5) of the vehicle and / or the PTO load, controlling the electric machine (12) so that it oscillates between a first rotational speed (ω1) and a second rotational speed (ω2) in order to generate heat.

Description

TECHNICAL FIELD

[0001] The present disclosure generally relates to a method for heating a powertrain and / or subsystem of a vehicle. The present disclosure further generally relates to a control arrangement configured for heating a powertrain and / or subsystem of a vehicle.

[0002] Furthermore, the present disclosure generally relates to a computer program and a computer-readable medium. The present disclosure also generally relates to a vehicle. BACKGROUND

[0003] Efforts to reduce emissions and improve fuel economy in heavy vehicles such as trucks and buses have led to the development of vehicles whose powertrains include one or more electric machines serving as propulsion units, configured to be powered by energy storage devices. Examples of such vehicles include, but are not limited to, battery electric vehicles (BEVs) and various hybrid electric vehicles (HEVs).

[0004] Cold starts, i.e., starts at low temperatures, are often problematic for all-electric or hybrid vehicle powertrains. When the powertrain and its components are cold, they cause greater power losses due to frictional losses. These increased power losses increase energy consumption, which in turn reduces the vehicle's potential operating range for the energy stored in the vehicle. Furthermore, operating with a cold powertrain can excessively increase wear on the powertrain components, thus reducing its service life.

[0005] The powertrain of an electric vehicle can also become cold during vehicle operation, especially in cold climates, which can have essentially the same effects as described above for cold starts.

[0006] The electric motor of the vehicle's powertrain is typically powered by an energy storage device. One of the main factors that can reduce the charge / discharge performance of an energy storage device is a temperature drop below the temperature range for which the energy storage device is designed. Therefore, energy storage devices in vehicles must be conditioned to deliver sufficient charge and power. This is often achieved using an external electric heater, fuel burner, or heat pump. However, this requires additional external hardware, which can lead to additional complexity and cost.

[0007] Various thermal management systems configured to utilize the heat generated by the electric machine to heat various subsystems of a vehicle are already known. For example, a temperature control circuit for the electric machine can be integrated with a temperature control circuit of an energy storage device that supplies the electric machine and / or an air conditioning system for a passenger compartment. SUMMARY

[0008] The aim of the present invention is to provide an improved solution for heating a powertrain and / or a subsystem of a vehicle.

[0009] The object is achieved by the subject matter of the appended independent claim(s).

[0010] According to the present disclosure, a method for heating a powertrain and / or a subsystem of a vehicle is provided. The method is performed by a control arrangement. The vehicle includes an electric machine configured to provide motive power to one or more drive wheels of the vehicle and / or to provide power to a power take-off (PTO) load. The method includes a step of, when the electric machine is disconnected from the one or more drive wheels of the vehicle and / or the PTO load, controlling the electric machine to oscillate between a first speed and a second speed to thereby generate heat.

[0011] The process described here utilizes the electric motor's inertia to generate heat during rapid acceleration and deceleration. This allows the electric motor to be conditioned, and the generated heat can also be used to heat other components and / or systems of the vehicle. The process described here also has the advantage of requiring no additional hardware, such as an additional heater, and can therefore be used in all electric or hybrid vehicles, regardless of the vehicle's specifications.

[0012] The step of controlling the electric machine to oscillate between a first and a second speed may consist of controlling the electric machine to oscillate between a first and a second speed of a power speed curve of the electric machine. In this way, the first and second speeds can be operated at high power, which in turn enables high power output and thus high heat generation. The power speed curve may preferably be a maximum power speed curve of the electric machine, as this allows as much heat as possible to be generated by the electric machine.

[0013] For example, the first and second speeds of the power speed curve may be located on opposite sides of a speed corresponding to a peak of the electric machine's power speed curve. This allows the electric machine to oscillate around the maximum power speed, resulting in a significant heating effect.

[0014] If the power speed curve exhibits a plateau, at least one of the first and second speeds can lie within the plateau of the electric machine's power speed curve. This can, for example, facilitate control of the electric machine if the power speed curve is steep on one or more sides of the plateau, which in turn ensures high heating efficiency.

[0015] The step of controlling the electric machine to oscillate between a first speed and a second speed may alternatively include changing the direction of rotation of the electric machine. In such a case, the first speed is a positive speed while the second speed is a negative speed, or vice versa. This can reduce the frequency of the oscillation compared to an oscillation between two speeds (with the same direction of rotation) of a power speed curve, which in turn can reduce noise and / or wear of the electric machine.

[0016] The method may further include a step of using the heat generated by the electric machine to heat the vehicle subsystem. This, in turn, may improve the performance and / or efficiency of the subsystem.

[0017] The method described here also has the advantage that it can be applied while driving, which can be advantageous, for example, in cold climates. The method can be performed, for example, while the vehicle is coasting down. If the vehicle has a first drivetrain with the electric motor and a second drivetrain separate from the first drivetrain, the method can alternatively be performed while the vehicle is driven by the second drivetrain.

[0018] The present disclosure further relates to a computer program containing instructions which, when executed by a computer, cause the computer to perform the method described above.

[0019] The present disclosure further relates to a computer-readable medium containing instructions that, when executed by a computer, cause the computer to perform the method described above.

[0020] The present disclosure also provides a control arrangement configured to heat a powertrain and / or subsystem of a vehicle, the vehicle including an electric machine configured to provide motive power to one or more drive wheels of the vehicle and / or drive a power take-off load. The control arrangement is configured to, when the electric machine is disconnected from the one or more drive wheels of the vehicle and / or the power take-off load, control the electric machine to oscillate between a first speed and a second speed to thereby generate heat.

[0021] The control arrangement offers the same advantages as described above with reference to the corresponding method for heating a drive train and / or a subsystem of a vehicle.

[0022] As already mentioned, the first and second speeds may correspond to a first speed and a second speed of a power speed curve of the electric machine, preferably a maximum power speed curve of the electric machine. Alternatively, the first speed may be a positive speed while the second speed is a negative speed of the electric machine, or vice versa.

[0023] The present disclosure also relates to a vehicle having the control arrangement described above. The vehicle may comprise a single drivetrain or multiple separate vehicle drivetrains. The vehicle may comprise an electric machine configured to supply motive power to one or more drive wheels of the vehicle and optionally drive a power take-off load. In such a case, the electric machine is part of a drivetrain of the vehicle. Alternatively, the vehicle may also comprise an electric machine designed only to drive a power take-off load. In this case, the electric machine used to carry out the method described here is not part of the drivetrain of the vehicle.

[0024] The vehicle can be a land vehicle with a single vehicle unit or a land vehicle combination with at least two vehicle units. If the vehicle consists of more than one vehicle unit, one or more of these vehicle units may have their own drivetrain. The vehicle may, for example, be a heavy-duty vehicle. Furthermore, the vehicle can be a pure electric vehicle, a hybrid vehicle, or a vehicle powered exclusively by an internal combustion engine (although in this case with an electric power take-off).

[0025] Furthermore, the vehicle may be configured to be fully or partially controlled by a driver. Such a driver may be onboard the vehicle or remote from the vehicle, for example, in a control center or the like. Alternatively, the vehicle may be fully autonomous. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows schematically a side view of a vehicle, Fig. 2 shows schematically an example of a drive train of a vehicle, Fig. 3 is a flowchart schematically illustrating an exemplary embodiment of the method described herein, Fig. 4 shows schematically the time course of the speed of the electric machine when the method described here is carried out, Fig. Figure 5 shows a first example of a curve of the maximum power speed of an electric machine, Fig. Figure 6 shows a second example of a curve of the maximum power speed of an electric machine, and Fig. 7 schematically shows an exemplary embodiment of a device which comprises, consists of or can be contained in a control arrangement for carrying out the method described here. DETAILED DESCRIPTION

[0026] The invention is described in more detail below with reference to exemplary embodiments and the accompanying drawings. However, the invention is not limited to the exemplary embodiments discussed and / or shown in the drawings, but may be varied within the scope of the appended claims. Furthermore, the drawings are not to be considered to scale, as some features may be exaggerated to better illustrate the invention or its features.

[0027] A vehicle, as used in this disclosure, is any means that can be used to transport people and / or goods. A vehicle may consist of a single vehicle unit. Examples of a vehicle consisting of a single vehicle unit include, but are not limited to, a passenger car, a rigid truck, a tractor-trailer, a bus, a self-propelled trailer, or a self-propelled dolly. Alternatively, a vehicle may be a vehicle combination consisting of at least two vehicle units that are connected to each other while in motion. A vehicle combination may be a vehicle that includes a tractor vehicle and at least one trailer vehicle. Examples of vehicle combinations include, but are not limited to, a semi-trailer truck, a rigid truck pulling a semi-trailer with a dolly, or a vehicle combination consisting of a rigid truck and one or more trailers.

[0028] Vehicle drivelines typically consist of at least one drive unit connected to the vehicle's drive wheels via one or more gearboxes and various shafts. In addition to powering the vehicle, a vehicle driveline can also be used to power one or more auxiliary power consumers. Examples of auxiliary power consumers include, but are not limited to, pumps, cranes, concrete mixers, compressors, or similar. To enable the powering of one or more such auxiliary power consumers, the vehicle can have one or more power take-off shafts that are operatively connected to the vehicle's driveline and designed to transfer power from the vehicle's driveline to a connected auxiliary power consumer. It is also possible to install an electric power take-off shaft (sometimes referred to as an E-PTO) in a vehicle, which does not need to be connected to the vehicle's driveline.Instead, such an electric PTO includes a dedicated power source (i.e., an electric machine powered by an energy storage device) configured to power the auxiliary power load. For the purposes of this disclosure, the additional power load(s) described above, whether powered by a separate electric machine or by an electric machine in the vehicle's powertrain, are considered to constitute a PTO load when connected to the PTO.

[0029] The method described here was primarily developed for cases where the electric machine used to perform the method forms part of a vehicle's drivetrain. However, the same solution can also be used when the electric machine is contained in a power take-off shaft and is not connected to the vehicle's drivetrain, e.g., a power take-off shaft installed in a vehicle with an internal combustion engine.

[0030] The present disclosure relates to a method performed by a control arrangement for heating a drivetrain and / or subsystem of a vehicle. The vehicle includes at least one electric machine, which may be configured to supply motive power to one or more drive wheels of the vehicle and optionally also to supply a power take-off (PTO) load. Alternatively, the vehicle's electric machine may be configured to supply only a PTO load. In the latter case, the electric machine is not connected to the drive wheel(s) of the vehicle. The electric machine may typically be powered by an energy storage device. The electric machine may be speed-controlled by means of an inverter.The inverter enables the speed of the electric machine to be controlled by varying the frequency and / or voltage and / or phase of the voltage supplied to the electric machine. The inverter can use an intermediate circuit voltage (from the energy storage device) to generate alternating voltages of suitable frequency and amplitude.

[0031] In the event that the electric machine is configured to provide motive power to one or more drive wheels of the vehicle, the method described herein includes a step of, when the electric machine is disconnected from the one or more drive wheels of the vehicle, controlling the electric machine to oscillate between a first speed and a second speed to thereby generate heat. If the electric machine is configured to both provide motive power to one or more drive wheels of the vehicle and drive a PTO load, the step of controlling the electric machine to oscillate between a first speed and a second speed to thereby generate heat is performed when the electric machine is disconnected from the one or more drive wheels and the PTO load.

[0032] In the event that the electric machine is only configured to drive a PTO load (i.e., not configured to provide motive power to one or more drive wheels of the vehicle), the method includes a step of, when the electric machine is disconnected from the PTO load, controlling the electric machine to oscillate between a first speed and a second speed to thereby generate heat.

[0033] Stated differently, the method described herein includes a step of controlling the vehicle's electric machine to oscillate between a first speed and a second speed when the electric machine is not subject to a load, the load resulting from the electric machine being connected to one or more drive wheels of the vehicle and / or a PTO load. Instead, the method described herein relies on harnessing the inertia of the electric machine (and an associated inverter) to load the electric machine and thereby generate power. The generated power heats the electric machine and can also be used to heat various subsystems of the vehicle. The vehicle subsystem can be, for example, a temperature control loop (e.g., a cooling loop), a lubrication loop, an energy storage loop (e.g.,This could be, but is not limited to, a vehicle interior (e.g., a battery or similar) or a passenger compartment (e.g., a driver's cab). Controlling the electric machine to oscillate between the first and second speeds also means that energy is drawn from the energy storage device that powers the electric machine, which in turn contributes (albeit to a lesser extent) to the heating of such an energy storage device. This means that the energy storage device can be conditioned both from within the battery cells of the energy storage device, due to discharge, and from outside, e.g., through a temperature control circuit.

[0034] By controlling the electric machine to oscillate between a first speed and a second speed, what is meant in the present disclosure is that the electric machine is controlled to vary repeatedly and regularly between the first and second speeds, substantially without remaining at the first or second speed. The oscillation between the first and second speeds is achieved by rapidly accelerating and decelerating the electric machine. It should be noted that the transition from acceleration to deceleration, or vice versa, of the electric machine takes a certain amount of time. Therefore, "substantially without remaining at the first or second speed" should be interpreted here to mean that the duration at the first or second speed is less than 5 seconds, preferably less than 2 seconds.Preferably, the transition from acceleration to deceleration, or vice versa, should occur as quickly as possible. This is because the inertia of the electric machine is quickly overcome if it remains at a constant speed, which in turn removes the load on the electric machine and thus also results in no power being generated by the electric machine.

[0035] The method described here can be carried out when the vehicle is stationary, e.g. when starting the vehicle after a longer stop (e.g. overnight) or during a temporary stop (e.g. when loading, during a traffic check, or similar). However, the method can also be carried out while the vehicle is moving. For example, the method can be carried out while the vehicle is idling or, in the case of a hybrid drive, while the electric machine is decoupled from the drivetrain and the vehicle is driven by an internal combustion engine. If the vehicle comprises two separate drivetrains, the method described here can also be carried out while the vehicle is driven by the drivetrain that does not comprise the electric machine, which is controlled to oscillate between the first and second speeds.

[0036] According to a first embodiment of the method described here, the step of controlling the electric machine can be carried out such that it oscillates between a first speed and a second speed, which expediently comprises controlling the electric machine such that it oscillates between a first speed and a second speed of a power speed curve of the electric machine. In this way, the first and second speeds can be operated at high power, which in turn enables high power output and thus high heat generation. Furthermore, this avoids having to change the direction of rotation of the electric machine. This has the advantage that the electric machine does not have to pass the zero speed point, thereby limiting the available electric machine power. The comfort disturbance caused by inertia can also be reduced.

[0037] The power speed curve is preferably the maximum power speed curve of the electric machine so that as much heat as possible can be generated. As is known to those skilled in the art, a maximum power speed curve of an electric machine defines the limits of the electric machine. However, the present disclosure is not limited to controlling the electric machine to oscillate between a first and a second speed of the maximum power speed curve of the electric machine. For example, the power curve used could also be a power curve that deviates from the maximum power curve by a predetermined offset, e.g., by a preselected percentage or value. This could be the case, for example, when a power (or torque) limit is active for the electric machine, the inverter, and / or the energy storage device (configured to supply the electric machine).

[0038] According to a second embodiment of the method described herein, the step of controlling the electric machine to oscillate between a first speed and a second speed may include changing the direction of rotation of the electric machine. In other words, the first speed may be a positive speed, while the second speed may be a negative speed, or vice versa.

[0039] The method may further comprise a step in which the heat generated by the electric machine is used to heat a subsystem of the vehicle. This may improve the performance and / or efficiency of the subsystem. If the vehicle subsystem is, for example, an energy storage device, heating the energy storage device may improve the efficiency of the charge / discharge cycle and reduce the risk of damage to the energy storage device. The energy storage devices currently used in the automotive industry generally have a relatively narrow optimal temperature range and therefore sometimes need to be heated, for example in cold climates. If the subsystem is a lubricant circuit, heating the lubricant may, for example, reduce the pumping work required to circulate the lubricant within the circuit, which in turn reduces its energy consumption.If the subsystem is an air conditioning system for a passenger compartment, the energy consumption for heating the passenger compartment can also be reduced because less heat is required from a heating device in the system.

[0040] The implementation of the method described herein for heating a powertrain and / or a subsystem of a vehicle can be controlled by programmed instructions. These programmed instructions can take the form of a computer program which, when executed by a computer, causes the computer to effect the desired forms of control action. Such a computer can, for example, be included in the control arrangement described herein. In the present disclosure, a computer is understood to mean any hardware or hardware / firmware device implemented with processing circuitry, such as, for example, a processor.a processor, central processing unit (CPU), controller, arithmetic logic unit (ALU), digital signal processor, microcomputer, field-programmable gate array (FPGA), system-on-chip (SoC), programmable logic unit, microprocessor, application-specific integrated circuit, or any other device capable of performing operations electronically in a defined manner.

[0041] The programmed instructions described above, which may take the form of a computer program, may be stored on a computer-readable medium. Therefore, the present disclosure also relates to a computer-readable medium having stored thereon instructions that, when executed by a computer, cause the computer to perform the method described herein for heating a powertrain and / or subsystem of a vehicle. The computer-readable medium may be a non-transitory computer-readable medium, such as a tangible electronic, magnetic, optical, infrared, electromagnetic, and / or semiconductor system, device, and / or apparatus.

[0042] The present disclosure further relates to a control arrangement configured to heat a powertrain and / or subsystem of a vehicle. The control arrangement may be configured to perform each of the steps of the method described herein for heating a powertrain and / or subsystem of a vehicle.

[0043] More specifically, a control arrangement is provided that is configured to heat a drivetrain and / or subsystem of a vehicle. The vehicle includes an electric machine that is configured to provide motive power to one or more drive wheels of the vehicle and / or to drive a power take-off load. The control arrangement is configured to, when the electric machine is disconnected from the one or more drive wheels of the vehicle and / or the power take-off load, control the electric machine to oscillate between a first speed and a second speed to thereby generate heat.

[0044] The control arrangement may comprise one or more control units. If the control arrangement comprises a plurality of control units, each control unit may be configured to control a specific function / step, or a specific function / step may be distributed among more than one control unit. The control arrangement may be a control arrangement for an electric machine or for a drivetrain including the electric machine. Alternatively, the control arrangement may be any other control arrangement of the vehicle, but configured to communicate with the electric machine for the purpose of carrying out the method described herein.

[0045] Fig. 1 schematically shows a side view of a vehicle 1, which is illustrated here as a tractor unit. The vehicle 1 may comprise a first vehicle unit 2, illustrated here as a tractor unit, and a second vehicle unit 3, illustrated here as a semi-trailer. The first vehicle unit 2 comprises a vehicle driveline configured to supply drive power to one or more drive wheels 4 of the first vehicle unit 2. Furthermore, the second vehicle unit 3 may optionally also comprise a vehicle driveline configured to supply drive power to one or more drive wheels 5 of the second vehicle unit 3. If present, the vehicle driveline of the second vehicle unit 3 may have the same configuration as the vehicle driveline of the first vehicle unit 2 or a different configuration.

[0046] Fig. Figure 2 schematically shows an example of a vehicle drive train 10, such as a vehicle drive train of the first vehicle unit 2 of the Fig. 1. The vehicle drivetrain 10 includes at least one electric machine 12 that can be powered by an energy storage device (not shown). The electric machine 12 is configured to transmit drive power to one or more drive wheels 4 via a transmission unit 14 and a drive shaft 16. The transmission unit 14 can optionally be connected to the drive shaft via a differential 15. The transmission unit 14 can be a single-speed transmission or a multi-speed transmission. The transmission unit 14, the optional differential 16, and the drive shaft 16 are all components of the vehicle drivetrain 10. Although not shown in the figure, the vehicle drivetrain 10 can also include an internal combustion engine, if desired. The vehicle drivetrain 10 can, for example, be a parallel hybrid drivetrain or a series hybrid drivetrain.

[0047] Furthermore, the vehicle drivetrain 10 can optionally include a power take-off shaft 18 connected to the electric machine 12. Using the power take-off shaft 18, the electric machine 12 can also be configured to supply an auxiliary power consumer 19. It should be noted that the auxiliary power consumer is not a component of the vehicle drivetrain 10.

[0048] The vehicle drivetrain 10 may further include a control arrangement 100 configured to control parts of the vehicle drivetrain 10 or the entire vehicle drivetrain 10. The control arrangement 100 may, for example, be configured to control at least the electric machine 12. The control arrangement 100 may be configured to perform the method described herein for heating a drivetrain and / or a subsystem of a vehicle.

[0049] Fig. Figure 3 schematically shows an exemplary embodiment of the method described here for heating a powertrain and / or a subsystem of a vehicle. Optional steps are indicated by dashed lines.

[0050] The method may include a step S101 in which it is determined whether a command to heat the powertrain and / or a subsystem of the vehicle using the electric machine has been generated. If no such command has been generated, the method may return to the start. However, if the command has been generated, the method may continue to a subsequent step.

[0051] The method may also include a step S102 in which the electric machine is disconnected from the drive wheel(s) of the vehicle and any PTO load, if it is not already disconnected therefrom.

[0052] The method includes a step S103 in which the electric machine is controlled to oscillate between a first speed and a second speed to generate heat. Step S103 is performed while the electric machine is disconnected from the vehicle's drive wheel(s) and any PTO load.

[0053] The method may further comprise a step S104 in which the heat generated by the electric machine is used to heat a subsystem of the vehicle.

[0054] The procedure can then be terminated.

[0055] Fig. Figure 4 schematically shows the speed of the electric machine over time when the electric machine is controlled to oscillate between a first speed ω1 and a second speed ω2 according to the method described here. As can be seen from the figure, the electric machine is repeatedly accelerated and decelerated.

[0056] Depending on the configuration of an electric machine, its maximum power and speed curve can take different shapes. In general, maximum power increases with speed up to a certain speed, which can define a maximum peak power or the beginning of a plateau with constant, increasing, or decreasing power with increasing speed. At speeds above the peak or plateau, maximum power decreases again as the electric machine's speed increases.

[0057] Fig. Figure 5 schematically shows an example of a curve of the maximum power speed 20 of an electric machine, this curve having a single maximum peak 22. In such a case, the first speed ω1 and the second speed ω2, between which the electric machine oscillates (as shown by the arrow), can be on opposite sides of the peak 22 to achieve the highest heating effect.

[0058] Fig. 6 schematically shows a second example of a maximum power speed curve 20 of an electric machine, wherein the maximum power speed curve includes a plateau 24. The plateau 24 is shown here as a plateau with constant power. However, it should be noted that the plateau 24 may alternatively have increasing or decreasing power with increasing speed of the electric machine. If the slope of the power speed curve 20 is steep on one side of the plateau 24, as shown in the figure at speeds above the plateau 24, it may be advantageous to have one of the speeds within the plateau 24, e.g., to reduce the risk of overspeed of the electric machine. In the figure, the second speed ω2 is shown as lying within the plateau 24.If the power speed curve 20 is steep on both sides of the plateau 24, both the first and second speeds ω,1 ω2 can lie within the plateau. Of course, it is also possible for the first and second speeds ω,1 ω2 to both lie outside the plateau; in this case, preferably on opposite sides of the plateau.

[0059] Fig. 7 schematically shows an exemplary embodiment of a device 500. The control arrangement 100 described above can, for example, comprise the device 500, consist of the device 500, or be contained in the device 500.

[0060] The device 500 includes a non-volatile memory 520, a data processing unit 510, and a random access memory 550. The non-volatile memory 520 has a first memory element 530 in which a computer program, e.g., an operating system, is stored for controlling the function of the device 500. The device 500 further includes a bus controller, a serial communication port, I / O means, an A / D converter, a time and date input and transmission unit, an event counter, and an interrupt controller (not shown). The non-volatile memory 520 also has a second memory element 540.

[0061] A computer program P is provided that includes instructions for heating a powertrain and / or a subsystem of a vehicle, the vehicle including an electric machine configured to provide motive power to one or more drive wheels of the vehicle and / or drive a power take-off load. The computer program includes instructions for, when the electric machine is disconnected from the one or more drive wheels of the vehicle and / or the power take-off load, controlling the electric machine to oscillate between a first speed and a second speed to thereby generate heat.

[0062] The program P can be stored in executable form or in compressed form in a memory 560 and / or in a random access memory 550.

[0063] The data processing unit 510 can execute one or more functions, ie the data processing unit 510 can execute a specific part of the program P stored in the memory 560 or a specific part of the program P stored in the read / write memory 550.

[0064] The data processing unit 510 can communicate with a data port 599 via a data bus 515. The non-volatile memory 520 is provided for communication with the data processing unit 510 via a data bus 512. The separate memory 560 is provided for communication with the data processing unit 510 via a data bus 511. The read / write memory 550 is intended to communicate with the data processing unit 510 via a data bus 514. Communication between the individual components can take place via a communication link. A communication link can be a physical connection such as an optoelectronic communication line or a non-physical connection such as a wireless connection, e.g., a radio or microwave link.

[0065] When data is received via data port 599, it can be temporarily stored in second memory element 540. Once the received input data has been temporarily stored, data processing unit 510 is ready to execute the code as described above.

Claims

[1] Method, carried out by a control arrangement (100), for heating a drive train (10) and / or a subsystem of a vehicle (1), wherein the vehicle (1) comprises an electric machine (12) configured to supply one or more drive wheels (4, 5) of the vehicle (1) with driving power and / or to drive a power take-off load, the method comprising a step: when the electric machine (12) is disconnected from the one or more drive wheels (4, 5) of the vehicle (1) and / or the PTO load, controlling (S103) the electric machine (12) so that it oscillates between a first speed (ω1) and a second speed (ω2) to thereby generate heat. [2] The method of claim 1, wherein the step of controlling (S103) the electric machine (12) to oscillate between a first speed (ω1) and a second speed (ω2) comprises controlling the electric machine (12) to oscillate between a first speed (ω1) and a second speed (ω2) of a power speed curve of the electric machine (12); wherein the power speed curve is preferably a maximum power speed curve (20) of the electric machine (12). [3] The method of claim 2, wherein the first and second speeds (ω1, ω2) of the power speed curve are located on opposite sides of a speed corresponding to a peak (22) of the power speed curve of the electric machine (12). [4] Method according to claim 2, wherein at least one of the first and second rotational speeds (ω1, ω2) lies within a plateau (24) of the power speed curve of the electric machine (12). [5] The method of claim 1, wherein the step of controlling (S103) the electric machine (12) to oscillate between a first speed (ω1 ) and a second speed (ω2 ) comprises changing the direction of rotation of the electric machine (12). [6] Method according to one of the preceding claims, further comprising using (S104) the heat generated by the electric machine (12) to heat the subsystem of the vehicle (1). [7] Method according to one of the preceding claims, wherein the method is carried out while the vehicle (1) is in motion. [8] The method of claim 7, wherein the method is performed during idle. [9] Method according to claim 7, wherein the vehicle (1) includes: a first drive train (10) comprising the electric machine (12), and a second drive train which is separate from the first drive train (10), and wherein the method is carried out while the vehicle (1) is driven by the second drive train. [10] A computer program comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any one of the preceding claims. [11] A computer-readable medium containing instructions which, when executed by a computer, cause the computer to carry out the method of any one of claims 1 to 9. [12] Control arrangement (100) configured to heat a drive train (10) and / or a subsystem of a vehicle (1), wherein the vehicle (1) comprises an electric machine (12) configured to supply one or more drive wheels (4, 5) of the vehicle (1) with driving power and / or to drive a power take-off load, wherein the control arrangement (100) is configured to, when the electric machine (12) is disconnected from the one or more drive wheels (4, 5) of the vehicle (1) and / or the PTO load, control the electric machine (12) to oscillate between a first speed (ω1) and a second speed (ω2) to thereby generate heat. [13] Control arrangement (100) according to claim 10, wherein the first and second speeds correspond to a first speed (ω1) and a second speed (ω2) of a power speed curve of the electric machine (12); wherein the power speed curve is preferably a maximum power speed curve of the electric machine (12). [14] Control arrangement (100) according to 12, wherein the first speed (ω1) is a positive speed and the second speed (ω2) is a negative speed or vice versa. [15] Vehicle (1) with the control arrangement (100) according to one of claims 12 to 14.

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