Method and control device for transmitting power between electric machine in vehicle

Abstract

A method performed by a control device for powering a vehicle including at least one first electric machine configured to power a first wheel, and at least one second electric machine configured to power a second wheel. At least one first electric machine and at least one second electric machine in the vehicle are interconnected by means of a hydraulic connection that enables available power from the electric machines to be utilized by transmitting excess power provided by one or more electric machines to drive wheels or axles requiring additional power. As a result, improved performance of the vehicle may be achieved. The invention also relates to a control device, a vehicle comprising the control device, a computer program and a computer readable medium.

Description

Technical Field

[0001] The invention relates to a method and a control device for transmitting power between electric machines in a vehicle. The invention also relates to a computer program and a computer readable medium and a vehicle comprising such a control device. Background Art

[0002] The following background description constitutes a description of the background of the present invention; however, it does not necessarily constitute prior art.

[0003] The vehicle must be able to be driven safely and reliably under changing road conditions. Some electric vehicles, such as trucks and buses, are equipped with separate drivetrains, which can provide certain advantages, such as improved traction, enhanced maneuverability, and increased power distribution flexibility. By having a separate drivetrain, power can be directed to each axle or each wheel of the vehicle independently, allowing better traction control and optimized power delivery to wheels with grip. This arrangement can also enhance the maneuverability of the vehicle, because power can be selectively distributed to specific wheels or axles, thereby achieving improved handling in different driving scenarios. In addition, a separate drivetrain provides flexibility in power distribution, allowing adjustments to be made based on changing road conditions and driving requirements. Summary of the invention

[0004] It is an object of the present invention to provide a method and a control device for alleviating or resolving the disadvantages of conventional solutions.

[0005] According to a first aspect of the invention, the foregoing and further objects are achieved by a method for powering a vehicle, the vehicle comprising at least one first motor configured to power a first wheel, and at least one second motor configured to power a second wheel, wherein the at least one first motor and the at least one second motor are interconnected by means of a hydraulic connection, the method comprising for at least one vehicle driving condition:

[0006] Power is transmitted between the at least one first electric machine and the at least one second electric machine by means of the hydraulic connection.

[0007] It should be understood that, as will be further described, depending on the vehicle configuration, at least one first motor and at least one second motor can be used to provide power to one or more vehicle drive wheels and / or to one or more power consumption devices in the vehicle. At least one vehicle driving condition can be a condition indicating that excess power is available in one or more motors and that additional power is required to operate the vehicle to achieve the desired performance. The vehicle driving condition can, for example, be a condition indicating that additional power may be required to propel the vehicle according to the desired speed. The additional power can be propulsion power or braking power. For example, when there is such a driving condition, the maximum power that can be provided by the motor to the first vehicle drive wheel or axle may not be enough to start the vehicle or operate the vehicle at the desired speed. At the same time, excess power may be available in another motor (for example, a motor that provides power to the second vehicle drive wheel with limited force, for example, due to being located on a low friction road surface). The vehicle driving condition may, for example, be related to an uneven load on a tilted road section, a smooth road section or a vehicle drive wheel.

[0008] Typically, when a vehicle is powered by a single motor or multiple mechanically interconnected motors, and when such a driving condition is detected, the power provided can be redistributed between the wheels or axles to enhance the performance of the vehicle. However, in configurations where no such mechanical connection between motors is available, such as on a vehicle with more than one driven axle driven by a separate propulsion unit, the maximum power of the vehicle may not be utilized, resulting in degraded vehicle performance.

[0009] According to the invention, the electric machines in a vehicle are interconnected by means of a hydraulic connection which enables the available power from the hydraulically interconnected electric machines to be utilized by transferring excess power provided by one or more electric machines to drive wheels or axles requiring additional power. Thus, improved performance of the vehicle can be achieved.

[0010] In an embodiment of the present invention, when the grip of the first wheel is different from the grip of the second wheel, the vehicle driving condition occurs, and the method further comprises:

[0011] When the grip of the second wheel exceeds the grip of the first wheel, power is transferred from the at least one first motor to the at least one second motor, and vice versa.

[0012] It will be appreciated that the grip of a wheel corresponds to a measure of how well the wheel maintains its grip on a surface while in motion. Wheel grip is critical to the performance of a vehicle as it directly affects its ability to accelerate, decelerate and maneuver effectively. When a wheel has good grip, it means that it can maintain traction with the surface, allowing it to transmit the forces required for propulsion, braking and steering.

[0013] Factors that may affect wheel grip include the nature of the surface, e.g. rough, smooth, dry, wet etc., the condition of the wheel, i.e. tyre mass, tread depth, tyre pressure and external forces acting on the wheel, e.g. vehicle load.

[0014] For example, when the above factors are different for different wheels, uneven grip on the wheels may occur. For example, the load on the wheels may be uneven, or parts of the surface of the road section on which the vehicle travels may be smooth. Such uneven grip on the wheels may affect the handling, performance and safety of the vehicle.

[0015] Some potential consequences of uneven grip involve reduced traction on certain wheels, which can result in reduced acceleration and braking performance of the vehicle. Additionally, wheels with better grip may experience excessive wear and tear, while wheels with poor grip may experience less wear. This can result in the need to replace tires prematurely, and may also affect the overall balance of the vehicle.

[0016] By transferring power from the at least one first electric machine to the at least one second electric machine when the grip of the second wheel exceeds the grip of the first wheel, and vice versa, more power will be transferred to the wheel with better grip. Thus, the energy usage of the vehicle is optimized by minimizing unnecessary wheel slip or spin. This can lead to improved energy efficiency and increased electric range in a hybrid or electric vehicle.

[0017] In addition, the size of the vehicle can be designed to have a smaller motor compared to a traditional driveline configuration. This is because the invention allows for more precise control of the distribution of the total power in the vehicle to the individual wheels / axles, which can compensate for the reduced power output of the smaller motor. This can help save costs during the production of the vehicle and reduce the overall weight of the vehicle. Lighter vehicles generally have improved energy efficiency and handling. They may also require less energy to operate, which can extend the vehicle's range.

[0018] In an embodiment of the invention, the first wheel and the second wheel are located on a common axle.

[0019] This means that the power generated by the at least one first motor and the at least one second motor can be distributed between the wheels on the same axle so that more power is applied to the wheels with higher grip to maximize traction. By applying more power to the wheels with higher grip or wheels that need more power, the stability and performance of the vehicle can be improved, especially in challenging road conditions such as wet or slippery surfaces. This can enhance driving safety and confidence.

[0020] In an embodiment of the invention, the first wheel is a wheel of a first axle of the vehicle and the second wheel is a wheel of a second axle.

[0021] It should be understood that the first axle and the second axle connect and support wheels on opposite sides of the vehicle. Depending on the configuration of the vehicle, there are different types of axles used in the vehicle. Thus, the first axle and the second axle may be, for example, a front axle supporting the front wheels of the vehicle, a rear axle supporting the rear wheels of the vehicle, an axle on a rear vehicle, a retractable axle, and / or an axle of a driven electric axle that receives torque from one or more motors in the vehicle.

[0022] This means that the power generated by the at least one first electric machine and the at least one second electric machine can be distributed between different axles of the vehicle to improve the stability and performance of the vehicle.

[0023] In an embodiment of the invention, the first axle is mechanically decoupled from the second axle.

[0024] Mechanically decoupling the first axle from the second vehicle means that no power can be mechanically transmitted between the first axle and the second axle. Conventional torque vectoring between the different axles is therefore not possible. The invention makes it possible to distribute the power generated by the at least one first electric machine and the at least one second electric machine between the different axles. Thereby, in a vehicle configuration where such a distribution is otherwise not possible, the stability and performance of the vehicle are also improved.

[0025] In an embodiment of the invention, the at least one first electric machine is mechanically decoupled from the at least one second electric machine.

[0026] It will be appreciated that the at least one first electric machine is mechanically decoupled from the at least one second electric machine such that power cannot be mechanically transferred between the decoupled electric machines.

[0027] The invention makes it possible to distribute the power generated by at least one first motor and at least one second motor between different wheels and / or axles without a mechanical connection for transmitting the power. Thus, in vehicle configurations where such a distribution is otherwise impossible, the stability and performance of the vehicle are also improved.

[0028] In an embodiment of the invention, the at least one first electric machine and / or the at least one second electric machine are configured to provide power to a power take-off (PTO) by means of a hydraulically connected PTO, and wherein the vehicle driving conditions include a PTO power request, the method further comprising:

[0029] Power is transmitted from the at least one first electric machine or the at least one second electric machine to the hydraulically connected PTO.

[0030] This means that the PTO can be powered by any motor in the vehicle that has excess power. Thus, an efficient, flexible and reliable PTO power supply is provided.

[0031] In an embodiment of the invention, the amount of power transferred from the at least one first electric machine and / or the at least one second electric machine via the hydraulic connection is based on one or more parameters related to vehicle driving conditions.

[0032] Thereby, the power generated in the at least one first electric machine and the at least one second electric machine may be managed in an efficient and reliable manner.

[0033] In an embodiment of the present invention, the parameters related to the vehicle driving condition include:

[0034] - a rotational speed of the at least one first electrical machine and / or the at least one second electrical machine,

[0035] - wheel slip of the first wheel and / or the second wheel,

[0036] - the weight of the vehicle,

[0037] - the inclination of the approaching road section,

[0038] - the rate or rate of change of acceleration requests,

[0039] - the available power transferable between said vehicle and the road,

[0040] - Vehicle driving mode,

[0041] -Road conditions for the upcoming road section,

[0042] - vehicle steering angle,

[0043] - the loads on the axles of the vehicle, and / or

[0044] - A power request to a PTO connected to said at least one first electric machine and / or to said at least one second electric machine.

[0045] Such parameters, ie vehicle-related parameters and / or parameters related to the approaching road section, can be obtained in the vehicle according to conventional solutions. Thus, the occurrence of a vehicle driving situation can be determined in an efficient and reliable manner.

[0046] In an embodiment of the present invention, the method further comprises:

[0047] The at least one first electric machine is disconnected from the first wheel and / or the at least one second electric machine is disconnected from the second wheel before power is transferred from the disconnected electric machine through the hydraulic connection.

[0048] Thus, excess power may also be efficiently transferred from the electric motor when power would not be transferred to the wheels to which the electric motor is configured to provide power.

[0049] In an embodiment of the present invention, one or both of the at least one first motor and the at least one second motor are configured to power a hydraulic pump for providing hydraulic fluid to a hydraulic motor connected to a wheel driven by the other of the at least one first motor and the at least one second motor, thereby transferring power from one of the at least one first motor and the at least one second motor to the other.

[0050] Thereby, power may be transferred from or to one or both of the at least one first electric machine and the at least one second electric machine by means of the hydraulic connection.

[0051] According to a second aspect, the invention relates to a control device for powering a vehicle, the vehicle comprising at least one first electric machine configured to power a first wheel, and at least one second electric machine configured to power a second wheel, wherein the at least one first electric machine and the at least one second electric machine are interconnected by means of a hydraulic connection, the control device being configured to:

[0052] Power is transmitted between the at least one first electric machine and the at least one second electric machine by means of the hydraulic connection.

[0053] It should be understood that all embodiments described for the method aspects of the present invention are also applicable to at least one of the control device aspects of the present invention. Therefore, all embodiments described for the method aspects of the present invention can be performed by a control device, which can also be a control device, i.e., a device. The control device and its embodiments have advantages corresponding to those described above for the method and its embodiments.

[0054] According to a third aspect of the invention, the foregoing and further objects are achieved by a vehicle comprising the control device of the second aspect.

[0055] According to a fourth aspect, the invention relates to a computer program comprising instructions for causing a computer to perform a method according to the first aspect when said program is executed by said computer.

[0056] According to a fifth aspect, the invention relates to a computer readable medium comprising instructions which, when executed by a computer, cause the computer to perform the method according to the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings, in which like reference numerals are used for like components, and in which:

[0058] Figure 1a An example vehicle is shown in which embodiments of the invention may be implemented.

[0059] Figure 1b A vehicle configuration is shown in which an embodiment of the present invention may be implemented.

[0060] Figure 1c Additional vehicle configurations are shown in which embodiments of the invention may be implemented.

[0061] Figure 2a A flow chart showing a method for controlling an electric powertrain of a vehicle in an idling state according to an embodiment of the present invention.

[0062] Figure 2b A flow chart showing a method for controlling an electric powertrain of a vehicle in an idling state according to another embodiment of the present invention.

[0063] Figure 3 An example of power transmission between motors in a vehicle according to an embodiment of the present invention is shown.

[0064] Figure 4a An example of power transmission based on slip differential actuation of vehicle drive wheels according to an embodiment of the present invention is shown.

[0065] Figure 4b An example of power transmission based on rotation speed difference actuation of motors in a vehicle according to an embodiment of the present invention is shown.

[0066] Figure 5 A control device is shown in which a method according to any of the embodiments described herein may be implemented. DETAILED DESCRIPTION

[0067] Generally, in electric vehicles, it is advantageous to be able to distribute the power generated in the vehicle to avoid costly oversizing of the vehicle's power source. For example, if one wheel or one axle lacks grip or has very little traction, it would be desirable in some cases to transfer more power to the wheel or axle with grip. In applications where grip is sometimes limited, differential locks, torque vectoring, or braking individual wheels can be used to distribute torque to the wheel or axle with the most grip. On vehicles with more than one driven axle, inter-axle differential locks are often used to transfer power to all wheels and thereby maximize traction.

[0068] On electric vehicles driven by a single motor, the maximum propulsion power of the vehicle is sometimes impossible to exploit. If one axle lacks friction, the motor supplying power to this axle cannot transfer power to the axle or wheel with higher grip unless there is a mechanical connection between the motor and the axle or wheel with higher grip. The possibility of having such a mechanical connection for power transfer is sometimes limited due to factors such as large axle distances, lack of space in the vehicle chassis or other axle configuration limitations.

[0069] It is therefore an object of the present invention to provide a method and a control device for powering a vehicle such that these problems are at least partially solved.

[0070] The embodiments given in this paper will be used to illustrate Figure 1a A vehicle 100 is shown. The vehicle 100 may be an electric vehicle, such as a truck or a bus. Figure 1a Not shown in FIG, but the vehicle 100 may be equipped with a trailer. The vehicle may alternatively be a sedan. Figure 1a The vehicle 100 shown in FIG. 1 may include a powertrain 110 a configured for an electric vehicle such as a battery electric vehicle. The powertrain may include an electric motor system including at least one first electric machine 101 a and may be configured to apply propulsion power and / or regenerative power, for example, to provide torque to one or more wheels 111 a, 111 b of the vehicle 100. It should be understood that the vehicle 100 may include more than Figure 1a The at least one first electric machine 101a may be connected to at least one energy storage device B in a conventional manner, the at least one energy storage device being configured to provide power to the at least one first electric machine 101a.

[0071] The at least one first electric machine 101 a may be arranged substantially anywhere as long as torque is provided to one or more wheels of the vehicle.

[0072] At least one first motor 101a can be connected to a gearbox 103 (via an input shaft of the gearbox 103) via an output shaft 102, for example, in a conventional manner. A propeller shaft 104 connected to the output shaft of the gearbox 103 drives drive wheels 111a, 111b via an axle A1, which connects and supports the drive wheels 111a, 111b of the vehicle 100. Axle A1 includes a central gear 105 and drive shafts 106a, 106b. The central gear 105 (e.g., a conventional differential) is connected to the propeller shaft 104, distributing power to the drive shafts 106a, 106b. The power provided by the at least one first motor 101a is thus transmitted to the drive wheels 111a, 111b. It should be understood that the vehicle 100 can be arranged in any known manner, such as without a conventional differential and / or gearbox, without limiting the scope of the present invention. The vehicle can be configured with one or more drive shafts, and each driven shaft can be powered individually by one or more motors.

[0073] Furthermore, the at least one first electric machine 101a may be disposed substantially anywhere along the powertrain 110a as long as torque is provided to one or more wheels, for example, as a hub motor configured to be directly integrated into the wheels 111a, 111b and provide individual power to the wheels.

[0074] Furthermore, the vehicle may include at least one second electric machine 101 b and / or be configured with at least one additional powertrain including at least one second electric machine 101 b, as will be described with reference to Figure 1b and 1c Explanatory.

[0075] The vehicle may also include a power take-off (PTO) 130 configured to transfer power from the power source to another piece of equipment (not shown) when coupled to the power source, as will be described in more detail in this disclosure. The power source that provides power to the PTO may be an electric motor, such as the above-described electric motor 101a, or another electric motor. The PTO may be powered by means of a hydraulic connection that connects the PTO to one or more electric motors.

[0076] Components of the powertrain 110 of the vehicle 100 and other components in the vehicle 100 may be controlled by a vehicle control system via a control device 120. The control device 120 may be distributed over several control units configured to control different parts of the vehicle 100. The control device 120 may, for example, comprise: a unit 121 for transferring power between at least one first electric machine and at least one second electric machine in the vehicle by means of a hydraulic connection; and other units arranged to perform the disclosed method steps of the invention, as further explained. The control device 120 will be combined with Figure 5 is described in further detail.

[0077] The vehicle 100 may also include one or more sensors 140 that provide sensor data to the vehicle control system, such as, for example, sensors for measuring the weight of the vehicle 100, the rotational speed of one or more motors in the vehicle, the wheel slip of one or more wheels of the vehicle 100, to name a few examples. In addition, the vehicle 100 may include a positioning system / unit 150. The positioning unit 150 may be based on a satellite navigation system, such as Navigation Signal Timing and Ranging (Navstar), Global Positioning System (GPS), Differential GPS (DGPS), Galeo, GLONASS, etc. Therefore, the positioning unit 150 may include a GPS receiver. It should be understood that the one or more sensors 140 and the positioning system / unit 150 described above may be configured to communicate with the control device 120 to provide relevant information to the control device 120.

[0078] It should be understood that the vehicle 100 may include additional units, components, such as Figure 1a The vehicle 100 may be configured, for example, to communicate with another external entity (e.g., by means of vehicle-to-vehicle V2V communication, vehicle-to-infrastructure V2I communication, vehicle-to-network V2X communication) and include the necessary means for communicating with another external entity. Figure 1aIn the figure, only the units / devices / entities of the vehicle 100 which are necessary for understanding the present invention are shown.

[0079] Now refer to Figure 2a The method 200 disclosed in Figure 1a The proposed solution is described with reference to the vehicle 100 disclosed in FIG. Figure 2a A flow chart of a method 200 for powering a vehicle 100 is shown, the vehicle 100 comprising at least one first motor 101a configured to power a first wheel 111a, and at least one second motor 101b configured to power a second wheel 111b, 112a, 112b, wherein the at least one first motor 101a and the at least one second motor 101b are interconnected by means of a hydraulic connection.

[0080] The method comprises, for at least one vehicle driving condition, transmitting power between at least one first electric machine 101 a and at least one second electric machine 101 b by means of a hydraulic connection in step 210 .

[0081] By transferring power between the motors 101a, 101b, the present invention is intended to increase the total power provided to the vehicle drive wheels during such driving conditions where the total power is otherwise limited, as shown in FIG. Figure 3 Explanatory.

[0082] Figure 3 An example of power transmission between electric machines in a vehicle 100 according to the method 200 of the present invention is shown. Figure 3 In the non-limiting example shown in , power transmission is performed between at least one first motor 101a providing power to a first driven shaft A1 and / or to a first wheel and at least one second motor 101b providing power to a second driven shaft A2 and / or to a second wheel. Figure 3 A curve P corresponding to the power applied by at least one first motor 101a over time is shown. A1 , a curve P corresponding to the power applied by at least one second motor 101b over time A2 , and a curve P corresponding to the total power applied by at least one first motor 101a and at least one second motor 101b over time SUM Therefore, in Figure 3 In, P SUM =P A1 +P A2 .

[0083] also, Figure 3 The power level P corresponding to the minimum total power required for propulsion or braking of the vehicle 100 is shown. REQ . Minimum power required P REQThis may be, for example, the power required to overcome the total driving resistance and / or to maintain a certain speed profile, or the power required to start or brake the vehicle 100 .

[0084] also, Figure 3 The power limits P1 and P3 during the current driving situation are shown, wherein P3 corresponds to the maximum power that can be applied to the axle A1 and / or the first wheel, and wherein P1 corresponds to the maximum power that can be applied to the axle A2 and / or the second wheel. The power limits P1 and P3 can be set, for example, by the road friction of the current road section. In addition, Figure 3 The maximum power P that can be delivered by the electric machine that powers the vehicle 100 is shown. MAX .exist Figure 3 In the example shown in FIG. 1 , the wheels of the first axle A1 and / or the first wheel may be located, for example, on a high friction road surface, and the power P applied to the first axle A1 and / or the first wheel A1 Therefore, the maximum power P that can be generated by the at least one first electric machine 101a may be MAX On the other hand, the wheels of the second axle A2 and / or the second wheel may be located on a low-friction road surface, which means that the power limit P1 is lower than the maximum power P that can be generated by the at least one second motor 101b. MAX If the power applied to the axle and / or wheel is above the power limit P1, the wheel is likely to spin, which may lead to an unstable situation and increased energy losses.

[0085] Therefore, if Figure 3 As can be seen in FIG. 1 , the total power P applied by at least one first motor 101a and at least one second motor 101b between time instances T0 and T1 is SUM Lower than P REQ , which means that during the current vehicle driving condition, the vehicle cannot be operated as required. When such a vehicle driving condition is detected, the present invention performs a power transmission between the at least one first motor 101a and the at least one second motor 101b by means of a hydraulic connection. Therefore, between the time instance T1 and the time instance T2, additional power is generated by the at least one second motor 101b, and the additional power is transmitted to the first axle A1, as shown in the curve P A2 This results in a total power P SUM At time instance T2, the sum of the power applied to the vehicle (including the power transferred from the at least one second motor 101b to the at least one first motor 101a) overcomes the total driving resistance and reaches the required minimum power P REQ .

[0086] In other words, the present invention may be applied in a vehicle 100 configured with two or more electric machines for propelling and / or braking the vehicle 100, wherein the two or more electric machines are interconnected by a hydraulic connection, as will be further explained.

[0087] The two or more electric machines may be configured in the vehicle 100 in various ways without limiting the scope of the present invention. Figure 1b-1c An example vehicle configuration including two or more electric machines, ie, at least one first electric machine 101 a and at least one second electric machine 101 b , is shown.

[0088] As previously explained, the at least one first motor 101a is configured to provide power to the first wheel 111a, and the at least one second motor 101b is configured to provide propulsion or braking power to the second wheel.

[0089] Figure 1b A vehicle configuration is shown that includes a first motor 101a, which is configured to provide power to a wheel 111a, which is here a first wheel. In addition, the vehicle includes a second motor 101b, which is configured to provide power to a second wheel 111b, which is here a second wheel. In an embodiment, the first wheel 111a and the second wheel 111b can be located on a common axle A1, such as Figure 1b In an embodiment, the first wheel 111a may be mechanically decoupled from the second wheel 111b.

[0090] In an embodiment, Figure 1c As shown in , the first wheel 111a may alternatively be one or more wheels of a first axle A1 of the vehicle 100, and the second wheels 112a, 112b may be one or more wheels of a second axle A2. In an embodiment, the first axle A1 may be mechanically decoupled from the second axle A2.

[0091] In an embodiment, the at least one first motor 101 a may be mechanically decoupled from the at least one second motor 101 b .

[0092] like Figure 1b-1c As shown in FIG. 1 , at least one first motor 101a and at least one second motor 101b may be interconnected via a hydraulic connection H. The hydraulic connection H may be used for power transfer between the interconnected motors. The hydraulic connection utilizes hydraulic fluid to transfer power from one motor to another motor. Figure 1b-1cAs shown in , the hydraulic connection may include at least one hydraulic pump 109a and at least one hydraulic motor 109b. In an embodiment, one or both of the at least one first motor 101a and the at least one second motor 101b may be configured to provide power to the hydraulic pump 109a for providing hydraulic fluid to the hydraulic motor 109b connected to the wheel driven by the other of the at least one first motor and the at least one second motor, thereby transferring power from one of the at least one first motor and the at least one second motor to the other.

[0093] In an embodiment, at least one first motor 111a and / or at least one second motor 111b may be configured to provide power to a hydraulically connected PTO 130, such as Figure 1b-1c as shown in .

[0094] Apart from Figure 2a In addition to step 210 of the method, the method 200 may include the following steps: Figure 2b Optional steps 202-208 shown in FIG. Therefore, Figure 2b 2 is a flow chart showing a method 200 according to another embodiment of the present invention. It should be noted that: Figure 2b The method steps shown in and described herein do not necessarily have to be performed in Figure 2b These steps can be performed in essentially any suitable order, as long as the physical requirements and information required to perform each method step are available when the step is performed.

[0095] As previously explained, the method 200 of the present invention is performed when at least one vehicle driving condition has been detected. Figure 2b In optional step 202 , at least one driving condition that leads to execution of method 200 is detected.

[0096] In an embodiment, at least one vehicle driving condition that results in execution of method 200 may occur when the grip of the first wheel 111a is different from the grip of the second wheels 111b, 112a, 112b. When such a vehicle driving condition is detected, in step 210, power may be transferred from at least one first motor 101a to at least one second motor 101b when the grip of the second wheel 111b exceeds the grip of the first wheel 111a, and vice versa. Such a vehicle driving condition may be detected according to conventional methods, for example based on one or more parameters related to the vehicle driving condition further described in the present disclosure. Figure 4a and Figure 4b An example of such power transmission based on parameters related to vehicle driving conditions is shown in FIG.

[0097] The grip of the first wheel 111a is different from the grip of the second wheels 111b, 112a, 112b based on the wheel slip of the first wheel 111a and / or the second wheels 111b, 112a, 112b (e.g. Figure 4a ), or based on the speed of at least one first motor 101a and / or at least one second motor 101b (as shown in Figure 4b ) is detected. For example, power transfer can be performed when the difference in wheel slip ratios of the drive wheels or the difference in rotational speeds of the motors reaches a certain threshold. Such a difference in wheel slip ratio or motor speed can occur, for example, when the friction of the road surface of the first wheel is different from the friction of the road surface of the second wheel. In another example, such a difference may occur when the load on the axle or wheel becomes uneven. The load between axles or wheels may become uneven in several situations, including uneven load distribution when the vehicle is traveling on an inclined or uneven road surface, during braking and acceleration, and when turning. In addition, the load between axles or wheels may change when one or more axles are raised.

[0098] Figure 4a The power transmission between two motors (e.g., at least one first motor 101a and at least one second motor 101b) over time based on the difference in wheel slip ratios of driving wheels (e.g., first wheel 111a and second wheel 111b, 112a, 112b) is shown. Figure 4a As can be seen from the lower curve B in FIG. 1 , the difference between the wheel slips of the vehicle drive wheels increases between time instance T0 and time instance T1. At time instance T1, the difference in wheel slip reaches the slip threshold S th . Slip threshold S th The magnitude of may depend on the application of the invention and may be available in the control system of the vehicle 100. As shown in the upper curve A, between time instances T0 and T1, i.e., when the difference in vehicle slip is below the slip threshold S th , no power transmission is performed between the at least one first motor 101a and the at least one second motor 101b. However, when the slip threshold S is reached th At time instance T1, when the grip of the second wheels 111b, 112a, 112b exceeds the grip of the first wheel 111a, power is transferred from the at least one first motor 101a to the at least one second motor 101b, and vice versa. th For example, it may be a value greater than 0% and less than 10%.

[0099] In a similar manner, Figure 4bThe power transfer over time between two motors (e.g., at least one first motor 101a and at least one second motor 101b) based on the speed difference of at least one first motor 101a and / or at least one second motor 101b is shown. It should be understood that when determining whether there is a difference in the speed of the motors 101a, 101b, any difference in the transmission ratio applied to the at least one first motor 101a and at least one second motor 101b needs to be taken into account. In the case where different transmission ratios are applied to the motors 101a, 101b, before the speed difference is established, the speed of the at least one first motor 101a and / or at least one second motor 101b needs to be compensated by the transmission ratio difference.

[0100] As in Figure 4b As can be seen from the lower curve D in FIG. 1 , the difference between the rotational speeds of at least one first motor 101a and at least one second motor 101b increases between time instance T0 and time instance T1. At time instance T1, the difference between the rotational speeds of at least one first motor 101a and at least one second motor 101b reaches a speed threshold ω. TH Speed ​​threshold ω TH The magnitude of may depend on the application of the invention and may be available in the control system of the vehicle 100. As shown in the upper curve C, between time instances T0 and T1, i.e., when the difference between the rotational speeds of the at least one first motor 101a and the at least one second motor 101b is below the speed threshold ω TH , the power transmission between the at least one first motor 101a and the at least one second motor 101b is not performed. However, when the speed threshold ω is reached TH When, at time instance T1, the grip of the second wheels 111b, 112a, 112b exceeds the grip of the first wheel 111a, power is transferred from the at least one first motor 101a to the at least one second motor 101b, and vice versa. Speed ​​threshold ω TH For example, it may be a value greater than 0% and less than 10%.

[0101] By transferring power between the wheels, the difference in vehicle slip is kept below the slip threshold S th , and the power applied in the vehicle increases.

[0102] In an embodiment, the vehicle driving condition may include a PTO power request when the at least one first motor 111a and / or the at least one second motor 111b is configured to provide power to the hydraulically connected PTO 130. When such a PTO power request is detected, power from the at least one first motor 101a or the at least one second motor 101b may be transferred to the hydraulically connected PTO 130.

[0103] The PTO is used to transfer power from a power source, such as an electric motor, to another piece of equipment, such as an auxiliary load that consumes energy, when power is requested. A PTO power request may involve activation of the PTO and may be manual, such as when the PTO is manually activated by the vehicle operator using a joystick or switch, or automatic based on, for example, a control algorithm in the vehicle depending on the specific application. For example, when the auxiliary load is a compressor of a refrigeration unit, the PTO may be automatically activated based on the temperature of the refrigeration unit. According to conventional methods, this PTO power request may be detected by or transmitted to the control device 120.

[0104] exist Figure 2b In step 204 of the embodiment, the magnitude of the power to be transmitted by the hydraulic connection is determined. In an embodiment, the magnitude of the power transmitted from at least one first motor 101a and / or at least one second motor 101b by the hydraulic connection can be based on one or more parameters related to the vehicle driving condition. For example, the magnitude of the power to be transmitted by the hydraulic pressure can be determined based on the power required to propel or brake the vehicle 100 on the approaching road section according to the required vehicle speed. The required vehicle speed can be based on the rate or rate of change of the acceleration request, for example. Considering the force acting on the vehicle 100 in the approaching road section when being propelled according to the required speed, the power required to propel or brake the vehicle 100 on the approaching road section can be predicted based on Newton's laws of motion. According to conventional solutions, the force can depend on parameters such as vehicle weight, vehicle steering angle, information related to the road condition of the upcoming road section, and road topology information, such as the inclination of the approaching road section. In addition, the magnitude of the power to be transmitted by the hydraulic connection can be based on the available power that can be transmitted between the vehicle and the road, that is, based on the maximum power that can be delivered by at least one first motor 101a and at least one second motor 101b. Furthermore, the power to be transferred through the hydraulic connection may be based on the vehicle drive mode.

[0105] When the power transferred through the hydraulic connection powers a hydraulically connected PTO, the amount of power to be transferred may be based on a power request to the PTO connected to the at least one first electric machine 101a and / or the at least one second electric machine 101b.

[0106] In other words, the parameters related to the vehicle driving condition may include vehicle internal parameters, such as the rotation speed of at least one first motor 101a and / or at least one second motor 101b, the wheel slip of the first wheel 111a and / or the second wheel 111b, the weight of the vehicle 100, the rate or rate of change of acceleration request, the available power that can be transmitted between the vehicle and the road, the vehicle driving mode, the vehicle steering angle, the load on the axle of the vehicle, and / or the power request for the PTO connected to the at least one first motor 101a and / or the at least one second motor 101b, and information related to the road section on which the vehicle is operating, such as the inclination of the approaching road section and the road condition of the upcoming road section. Such parameters can be obtained in the vehicle 100 according to many known ways that are all included in the scope of the present invention. The vehicle internal parameters are available in the control system of the vehicle. The information related to the road section on which the vehicle is operating can be obtained based on map data (e.g., a digital map including, for example, terrain information available from the vehicle 100) in combination with positioning information (e.g., GPS information). The positioning information may be used to determine the position of the vehicle 100 relative to the map data so that the road segment information may be extracted from the map data. In addition, such information may be detected by means of one or more sensors 140 (e.g. one or more cameras or one or more radars) that may be included in the vehicle 100. In addition, such information may be obtained from at least one other vehicle in front of the vehicle 100 and transmitted to the vehicle 100 using V2V communication, for example via at least one communication device.

[0107] exist Figure 2b In optional step 206, at least one first motor 101a is disconnected from the first wheel 111a and / or at least one second motor 101b is disconnected from the second wheels 111b, 112a, 112b before power is transferred from the disconnected motor via the hydraulic connection in step 210.

[0108] exist Figure 2b In optional step 208 of , when power is to be transferred between the motors, hydraulic pressure in the hydraulic connection is increased.

[0109] According to an aspect of the present invention, a control device 120 for providing power to a vehicle 100 is proposed. The vehicle comprises at least one first motor 101a configured to provide power to a first wheel 111a, and at least one second motor 101b configured to provide power to a second wheel 111b, 112a, 112b, wherein the at least one first motor 101a and the at least one second motor 101b are interconnected by means of a hydraulic connection, and the control device is configured to: for at least one vehicle driving condition:

[0110] The control device 120 comprises means 121 arranged to transfer 210 power between at least one first electric machine 101a and at least one second electric machine 101b by means of a hydraulic connection for at least one vehicle driving condition.

[0111] The control device 120 (e.g., device or control device) according to the present invention can be arranged to perform all method steps in the above, claims, and embodiments described herein. The control device 120 thus provides the above advantages for each respective embodiment. The present invention also relates to a vehicle 100 comprising the control device 120.

[0112] Now go to Figure 5 , which shows a control device 500 / 120, which may correspond to or may include the above-mentioned control unit 121 and other control units that perform the disclosed method steps of the invention. The control device 500 / 120 includes a computing unit 501, which may be composed of a processor or microcomputer of substantially any suitable type, such as a circuit for digital signal processing (digital signal processor, DSP), or a circuit with a predetermined specific function (application-specific integrated circuit, ASIC). The computing unit 501 is connected to a storage unit 502 arranged in the control device 500 / 120, which provides the computing unit 501 with, for example, stored program code and / or stored data that the computing unit 501 needs in order to be able to perform calculations. The computing unit 501 is also arranged to store partial or final results of the calculations in the storage unit 502.

[0113] In addition, the control device 500 / 120 is provided with means 511, 512, 513, 514 for receiving and transmitting input and output signals. These input and output signals may contain waveforms, pulses or other properties which may be detected as information by the means 511, 513 for receiving input signals and may be converted into signals which may be processed by the computing unit 501. These signals are then available to the computing unit 501. The means 512, 514 for transmitting output signals are arranged to convert signals received from the computing unit 501 so as to generate output signals by, for example, modulating the signal, which output signals may be transmitted to other parts and / or systems in the vehicle 100.

[0114] Each connection to the means for receiving and transmitting input and output signals may be constituted by one or more of a cable, a data bus (e.g., a controller area network (CAN) bus, a media oriented system transport (MOST) bus, or some other bus configuration); or by a wireless connection. Those skilled in the art will appreciate that the above-mentioned computer may be constituted by a computing unit 501, and the above-mentioned memory may be constituted by a storage unit 502.

[0115] The control system in a modern vehicle typically includes a communication bus system consisting of one or more communication buses for linking a plurality of electronic control units (ECUs) or controllers and various components located on the vehicle. Such a control system may include a large number of control units, and the responsibility for a particular function may be divided between more than one control unit. Therefore, a vehicle of the type shown typically includes many more control units than shown in FIGS. 1 and 5 , as is well known to those skilled in the art.

[0116] In the illustrated embodiment, the present invention may be implemented by one or more of the above-mentioned control units, such as control unit 121. However, the present invention may also be implemented in whole or in part in one or more other control units already present in vehicle 100, or in some control units dedicated to the present invention.

[0117] Here and in this document, units are generally described as being arranged to perform the steps of the method according to the invention. This also includes that these units are designed and / or configured to perform these method steps.

[0118] The control unit for implementing the present invention may be implemented as one control unit, or may be logically separated but physically implemented in the same unit, or may be arranged together both logically and physically. These units may correspond, for example, to groups of instructions that may be in the form of programming codes, which are respectively input into and utilized by the processor / computing unit 501 when the unit is active and / or used to perform its method steps.

[0119] Those skilled in the art will appreciate that the embodiments described herein for providing power to the vehicle 100 may also be implemented in a computer program that, when executed in a computer, instructs the computer to perform the method. The computer program is typically comprised of a computer program product 503 stored on a non-transitory / non-volatile digital storage medium, wherein the computer program is contained in a computer readable medium of the computer program product. The computer readable medium includes suitable memory, such as: read-only memory (ROM), programmable read-only memory (PROM), erasable PROM (EPROM), flash memory, electrically erasable PROM (EEPROM), hard disk unit, etc.

[0120] The invention is not limited to the embodiments described above. On the contrary, the invention relates to and covers all different embodiments included within the scope of the independent claims.

Claims

1. A method (200) for powering a vehicle, the vehicle comprising at least one first motor (101a) configured to power a first wheel (111a), and at least one second motor (101b) configured to power a second wheel (111b, 112a, 112b), wherein the at least one first motor (101a) and the at least one second motor (101b) are interconnected by means of a hydraulic connection, the method comprising, for at least one vehicle driving condition: Power is transmitted (210) between the at least one first motor (101a) and the at least one second motor (101b) by means of the hydraulic connection.

2. The method (200) of claim 1, wherein the vehicle driving condition occurs when the grip of the first wheel (111a) is different from the grip of the second wheel (111b, 112a, 112b), the method further comprising: When the grip of the second wheel exceeds the grip of the first wheel, power is transmitted from the at least one first motor (101a) to the at least one second motor (101b), and vice versa.

3. The method (200) according to claim 1 or 2, wherein the first wheel (111a) and the second wheel (111b) are located on a common axle.

4. The method (200) according to claim 1 or 2, wherein the first wheel (111a) is a wheel of a first axle of the vehicle and the second wheel (112a, 112b) is a wheel of a second axle.

5. The method (200) of claim 4, wherein the first axle is mechanically decoupled from the second axle.

6. The method (200) according to any one of the preceding claims, wherein the at least one first electric machine (101a) is mechanically decoupled from the at least one second electric machine (101b).

7. The method (200) according to any one of the preceding claims, wherein the at least one first electric machine (101a) and / or the at least one second electric machine (101b) are configured to provide power to a power take-off (PTO) (130) by means of a hydraulic connection, and wherein the vehicle driving condition comprises a PTO power request, the method further comprising: Power is transmitted from the at least one first motor (101a) or the at least one second motor (101b) to a hydraulically connected PTO (130).

8. A method (200) according to any of the preceding claims, wherein the amount of power transmitted from the at least one first motor (101a) and / or the at least one second motor (101b) through the hydraulic connection is based on one or more parameters related to the vehicle driving conditions.

9. The method (200) according to claim 8, wherein the parameters related to the vehicle driving condition include: - a rotational speed of the at least one first electric machine (101a) and / or the at least one second electric machine (101b), - wheel slip of the first wheel and / or the second wheel, - the weight of the vehicle (100), - the inclination of the approaching road section, - the rate or rate of change of acceleration requests, - the available power transferable between said vehicle and the road, - Vehicle driving mode, -Road conditions for the upcoming road section, - vehicle steering angle, and / or - the loads on the axles of the vehicle, and / or - a power request to a PTO (130) connected to the at least one first electric machine (101a) and / or the at least one second electric machine (101b).

10. The method (200) according to any one of the preceding claims, further comprising: The at least one first motor (101a) is disconnected from the first wheel (111a) and / or the at least one second motor (101b) is disconnected from the second wheel (111b, 112a, 112b) before power is transferred from the disconnected motor through the hydraulic connection (206).

11. A method (200) according to any one of the preceding claims, wherein one or both of the at least one first motor and the at least one second motor (101a, 101b) are configured to provide power to a hydraulic pump for providing hydraulic fluid to a hydraulic motor connected to the wheel driven by the other of the at least one first motor and the at least one second motor (101a, 101b), thereby transferring power from one of the at least one first motor and the at least one second motor (101a, 101b) to the other.

12. The method (200) of claim 10, wherein when power is to be transferred between the motors (101a, 101b), the hydraulic pressure in the hydraulic connection is increased.

13. A control device (120) for providing power to a vehicle, the vehicle comprising at least one first motor (101a) configured to provide power to a first wheel, and at least one second motor (101b) configured to provide power to a second wheel (111b, 112a, 112b), wherein the at least one first motor (101a) and the at least one second motor (101b) are interconnected by means of a hydraulic connection, the control device being configured to: Power is transmitted (210) between the at least one first motor (101a) and the at least one second motor (101b) by means of the hydraulic connection.

14. A vehicle (100) comprising a control device (120) according to claim 13.

15. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform the method (200) according to any one of claims 1 to 12.

16. A computer-readable medium comprising instructions which, when executed by a computer, cause the computer to perform the method (200) according to any one of claims 1 to 12.

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