Apparatus and method for controlling an electric machine

Abstract

Embodiments of the invention provide an electric machine control system for a vehicle, the electric machine control system comprising one or more controllers, wherein the vehicle comprises an electric machine arranged to be selectively couplable to provide torque to at least one wheel of an axle of the vehicle, the control system comprising: an input device to receive a speed signal indicative of a speed of the vehicle; a processing device arranged to determine a desired coupling state of the electric machine to the at least one wheel of the axle (525) in dependence on the speed signal, wherein the processing device is arranged to determine the desired coupling state to be coupled in dependence on the speed signal being indicative of the speed of the vehicle being equal to or below a first low speed threshold (910), and to determine the desired coupling state to be uncoupled in dependence on the speed signal being indicative of the speed of the vehicle being above a second low speed threshold (920), wherein the second low speed threshold represents a speed of the vehicle greater than the first low speed threshold; and an output device arranged to output a coupling signal in dependence on the desired coupling state being coupled, the coupling signal being indicative of a request to couple the electric machine to the at least one wheel of the axle.

Description

Technical Field

[0001] This disclosure relates to the control of motors, and particularly, but not exclusively, to the coupling of control motors. Aspects of the invention relate to control systems, powertrains, vehicles, methods, and computer software. Background Technology

[0002] Vehicles powered by more than one power or traction source (e.g., an internal combustion engine and one or more electric motors) are becoming increasingly known. However, managing multiple traction power sources can present challenges.

[0003] The purpose of the embodiments of the present invention is to alleviate at least one or more problems of the prior art. Summary of the Invention

[0004] The present invention provides, in aspects and embodiments, a control system, a powertrain, a vehicle, a method, and computer software as described below.

[0005] According to one aspect of the invention, a motor control system for a vehicle is provided, the motor control system comprising: one or more controllers, wherein the vehicle includes a motor arranged to be selectively coupled to provide torque to at least one wheel of an axle of the vehicle; and a processing device arranged to determine the coupling state of the motor with at least one wheel of the axle. Advantageously, the processing device is arranged to determine the coupling of the motor with at least one wheel of the axle.

[0006] Optionally, the processing device is arranged to determine the desired coupling state as coupling based on a speed signal indicating that the vehicle speed is equal to or lower than a first low-speed threshold. Advantageously, the processing device is arranged to determine the coupling between the motor and at least one wheel of the axle as coupling at a lower speed.

[0007] According to one aspect of the invention, a motor control system for a vehicle is provided, the motor control system comprising one or more controllers, wherein the vehicle includes a motor arranged to be selectively coupled to provide torque to at least one wheel of an axle of the vehicle, the control system comprising: an input device for receiving a speed signal indicating a speed of the vehicle; a processing device arranged to determine a desired coupling state between the motor and at least one wheel of the axle based on the speed signal, wherein the processing device is arranged to determine the desired coupling state as coupled based on a speed signal indicating a vehicle speed equal to or below a first low-speed threshold, and to determine the desired coupling state as not requested based on a speed signal indicating a vehicle speed above a second low-speed threshold, wherein the second low-speed threshold represents a vehicle speed greater than the first low-speed threshold; and an output device arranged to output a coupling signal indicating a request to couple the motor to at least one wheel of the axle based on the desired coupling state as coupled. Advantageously, the processing device does not request the coupling state at higher motor speeds. Advantageously, two thresholds are used, thereby improving the control of coupling. Advantageously, the non-request is determined at higher speeds compared to a decoupled state.

[0008] The processing device can be arranged to determine the desired coupling state based on a speed signal indicating the vehicle speed between a first low-speed threshold and a second low-speed threshold, according to the most recently intersecting threshold of the first and second low-speed thresholds. Advantageously, excessive or frequent switching of the coupling state is prevented. Optionally, the processing device can be arranged to determine the desired coupling state as coupled when the most recently intersecting threshold is the first low-speed threshold. Advantageously, the coupling state is maintained when most recently selected. Optionally, the processing device can be arranged to determine the desired coupling state as not requested when the most recently intersecting threshold is the second low-speed threshold. Advantageously, the not-requested state is maintained when more recently selected.

[0009] The input device can be arranged to receive a signal indicating the coupling state of the motor and at least one wheel of the axle. Advantageously, the actual coupling state is indicated to the processing device.

[0010] The processing unit can be arranged to control the output device to output a coupling suppression signal based on a speed signal indicating that the vehicle speed is equal to or below a third low-speed threshold and a coupling state signal indicating that the motor is decoupled from at least one wheel of the axle. Advantageously, coupling is suppressed if the motor is decoupled at a very low speed.

[0011] Optionally, the processing device is arranged to control the output device to stop outputting the coupled suppression signal based on a speed signal indicating that the vehicle speed is equal to or higher than a fourth low-speed threshold. Advantageously, the suppression is eliminated as the vehicle speed increases.

[0012] The processing device is configured to determine the vehicle's deceleration rate based on the speed signal, and to determine a first low-speed threshold based on the vehicle's deceleration rate. Advantageously, the first low-speed threshold is adaptive to the deceleration rate.

[0013] The processing unit is arranged to increase a first low-speed threshold based on a deceleration rate equal to or greater than a predetermined deceleration rate. Advantageously, this provides a longer time to achieve coupling when the vehicle is decelerating at a faster rate.

[0014] According to one aspect of the invention, a powertrain is provided that includes the system described above.

[0015] According to one aspect of the invention, a vehicle is provided that includes a control system or powertrain as described above.

[0016] According to one aspect of the invention, a method for controlling the coupling of a motor for providing torque to at least one wheel of an axle of a vehicle is provided, the method comprising: receiving a speed signal indicating a speed of the vehicle; determining a desired coupling state between the motor and at least one wheel of the axle based on the speed signal, wherein the desired coupling state is determined to be coupled based on a speed signal indicating a vehicle speed equal to or lower than a first low speed threshold; and determining the desired coupling state to be unrequired based on a speed signal indicating a vehicle speed higher than a second low speed threshold, wherein the second low speed threshold represents a vehicle speed greater than the first low speed threshold.

[0017] The method includes outputting a coupling signal based on a desired coupling state of coupling, the coupling signal indicating a request to couple a motor to at least one wheel of the axle.

[0018] Optionally, the desired coupling state is determined based on the speed signal indicating the vehicle speed between a first low speed threshold and a second low speed threshold, according to the threshold that most recently intersects between the first low speed threshold and the second low speed threshold.

[0019] The method may include determining the desired coupling state as coupled when the most recently intersected threshold is a first low-speed threshold. The method may also include determining the desired coupling state as not requested when the most recently intersected threshold is a second low-speed threshold.

[0020] Optionally, the method includes receiving a signal indicating the coupling state of the motor and at least one wheel of the axle;

[0021] Optionally, the method includes outputting a coupling suppression signal based on a speed signal indicating that the vehicle speed is equal to or below a third low-speed threshold. The coupling status signal may indicate that the motor is decoupled from at least one wheel of the axle.

[0022] The method may include stopping the output of the coupling suppression signal based on a speed signal indicating that the vehicle speed is equal to or higher than a fourth low speed threshold.

[0023] Optionally, the method includes determining the vehicle's deceleration rate based on a speed signal. The method may also include determining a first low-speed threshold based on the vehicle's deceleration rate.

[0024] The processing device can be arranged to increase the first low-speed threshold based on the deceleration rate being equal to or greater than a predetermined deceleration rate.

[0025] According to another aspect of the invention, computer software is provided, which is arranged to perform the methods described above when executed by a computer. The computer software may be stored on a computer-readable medium. The computer software may be tangibly stored on a computer-readable medium.

[0026] Within the scope of this application, it is expressly intended that all aspects, embodiments, examples, and alternatives set forth in the preceding paragraphs, claims, and / or the following description and drawings, and in particular their various features, may be employed independently or in any combination. That is, all embodiments and / or features of any embodiment may be combined in any manner and / or combination, unless such features are incompatible. The applicant reserves the right to amend any initially filed claim or accordingly file any new claim, including the right to modify any initially filed claim to incorporate any feature subordinate to and / or incorporated into any other claim, even if not initially claimed in this manner. Attached Figure Description

[0027] One or more embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which:

[0028] Figure 1 A vehicle according to an embodiment of the present invention is shown;

[0029] Figure 2 A system according to an embodiment of the present invention is shown;

[0030] Figure 3 A control system according to an embodiment of the present invention is shown;

[0031] Figure 4 A diagram illustrating modules of a control system according to an embodiment of the present invention is shown;

[0032] Figure 5 A method according to an embodiment of the present invention is shown;

[0033] Figure 6 The operation of a module according to an embodiment of the present invention is illustrated;

[0034] Figure 7 The operation of the module according to an embodiment of the present invention is further illustrated;

[0035] Figure 8 The operation of another module according to an embodiment of the present invention is shown;

[0036] Figure 9 A method according to another embodiment of the present invention is shown;

[0037] Figure 10 A method according to yet another embodiment of the present invention is shown;

[0038] Figure 11 A method according to yet another embodiment of the present invention is shown;

[0039] Figure 12 A method according to an embodiment of the present invention is shown;

[0040] Figure 13 A method according to yet another embodiment of the present invention is shown;

[0041] Figure 14 A method according to yet another embodiment of the present invention is shown;

[0042] Figure 15 The operation of a module according to an embodiment of the present invention is shown; and

[0043] Figure 16 The operation of a system according to an embodiment of the present invention is illustrated. Detailed Implementation

[0044] Figure 1 A vehicle 100 according to an embodiment of the present invention is shown. The vehicle 100 provides space for one or more occupants within its passenger compartment. In some embodiments, the vehicle 100 can be manually driven by one of the occupants representing the driver of the vehicle 100, but in some embodiments, the vehicle 100 may have at least partial autonomous driving capability. As will be explained, the vehicle 100 is a hybrid electric vehicle (HEV) having an internal combustion engine for providing power torque and one or more electric motors or traction motors for at least partial electric drive. In some embodiments, the vehicle 100 may be fully electric, i.e., a battery electric vehicle (BEV) without an internal combustion engine.

[0045] Figure 2 A system 20 for a parallel-type HEV 10 is shown. System 20 at least partially defines the powertrain of the HEV. System 20 includes a control system 208. Control system 208 includes one or more controllers 10. Control system 208 may include one or more of a hybrid powertrain control module, an engine control unit, a transmission control unit, a traction battery management system, etc.

[0046] System 20 includes engine 202. Engine 202 is a combustion engine. The engine 202 shown is an internal combustion engine. The engine 202 shown includes three combustion chambers; however, in other examples, a different number of combustion chambers may be provided.

[0047] Engine 202 is operatively coupled to control system 208 so that control system 208 can control the output torque of engine 202. The output torque of engine 202 can be controlled, depending on the type of engine 202, by controlling one or more of the following: air-fuel ratio, ignition timing, lift valve lift, lift valve timing, throttle valve opening position, fuel pressure, turbocharger boost pressure, etc.

[0048] System 20 includes a vehicle transmission 204 for receiving output torque from engine 202. Vehicle transmission 204 may include an automatic or semi-automatic vehicle transmission. Vehicle transmission 204 includes a hydraulically coupled torque converter 217 between engine 202 and the gear train.

[0049] System 20 may include a differential (not shown) for receiving output torque from the gear train. The differential may be integrated into the vehicle transmission 204 as a transmission drive axle, or it may be provided separately.

[0050] Engine 202 is mechanically connected to or can be connected to a first set of wheels (FL, FR) via a first torque path 220. The first torque path 220 extends from the output of engine 202 to vehicle transmission 204, then to the wheel axle / drive shaft, and then to the first set of wheels (FL, FR). In cases of vehicle overspeed and / or friction braking, torque can flow from the first set of wheels (FL, FR) to engine 202. The torque flowing towards the first set of wheels (FL, FR) is positive, and the torque from the first set of wheels (FL, FR) is negative.

[0051] The first set of wheels (FL, FR) shown includes the front wheels, and the axle is a front transverse axle. Therefore, system 20 is configured to drive the front wheels by engine 202. In another example, the first set of wheels (FL, FR) includes the rear wheels (RL, RR). The first set of wheels (FL, FR) shown is a pair of wheels; however, a different number of wheels may be provided in other examples.

[0052] In the system 20 shown, no longitudinal (center) drive shaft is provided to make room for hybrid vehicle components. Therefore, the engine 202 cannot be connected to the second set of rear wheels (rear wheels RL, RR in the illustration). The engine 202 can be mounted laterally to save space.

[0053] A torque path connector 218, such as a clutch, is disposed inside and / or outside the bell-shaped housing of the vehicle transmission 204. The clutch 218 is configured to connect the torque path 220 between the engine 202 and the first set of wheels (FL, FR), and is also configured to disconnect the torque path 220 between the engine 202 and the first set of wheels (FL, FR). The system 20 can be configured to automatically actuate the clutch 218 without user intervention.

[0054] System 20 includes a first electric traction motor 216. The first electric traction motor 216 may be an AC induction motor, a permanent magnet motor, or other types of motor. The first electric traction motor 216 is located on the engine side of clutch 218.

[0055] The first electric traction motor 216 can be mechanically coupled to the engine 202 via a belt or chain. For example, the first electric traction motor 216 can be a belt-integrated starter generator (BiSG). In the illustration, the first electric traction motor 216 is located at the accessory drive end of the engine 202, opposite the vehicle drive end of the engine 202. In an alternative example, the first electric traction motor 216 is a crankshaft-integrated electric generator located at the vehicle drive end of the engine 202.

[0056] The first electric traction motor 216 is configured to apply positive torque to the crankshaft of the engine 202 and is also configured to apply negative torque to the crankshaft of the engine 202, for example, providing functions such as: increasing the output torque of the engine 202; deactivating (shutting off) the engine 202 when stopped or coasting; activating (starting) the engine 202; and performing regenerative braking in regenerative mode. In hybrid electric vehicle mode, both the engine 202 and the first electric traction motor 216 can be operated to simultaneously supply positive torque to increase the output torque. The first electric traction motor 216 may not be able to continuously drive purely electric, although in other embodiments, the first electric traction motor 216 may be able to drive purely electric, particularly in embodiments without the engine 202. One or both of the engine 202 and the first electric traction motor 216 are capable of providing torque to the first axle 221 of the vehicle.

[0057] However, when the torque path 220 between the engine 202 and the first set of wheels (FL, FR) is disconnected, the torque path 220 between the first electric traction motor 216 and the first set of wheels (FL, FR) is also disconnected.

[0058] Figure 2A second electric traction motor 212 is shown, which is configured to enable at least an electric vehicle mode including pure electric drive. In some, but not necessarily all, examples, the nominal maximum torque of the second electric traction motor 212 is greater than the nominal maximum torque of the first electric traction motor 216.

[0059] Even though the torque path 220 between the engine 202 and the first set of wheels (FL, FR) is disconnected by the clutch 218, the vehicle 10 can still be driven in electric vehicle mode because the second electric traction motor 212 is connected to at least one wheel. The at least one wheel can be one or both of the rear wheels (RL, RR) of the vehicle 100 associated with the second axle 222 of the vehicle 100.

[0060] The second electric traction motor 212 shown is configured to provide torque to the second set of wheels (RL, RR) shown on the second axle 222 of the vehicle. The second set of wheels (RL, RR) includes wheels that do not originate from the first set of wheels (FL, FR). The second set of wheels (RL, RR) shown includes rear wheels, and the second electric traction motor 212 is operable to provide torque via the rear lateral axial rear wheels (RL, RR) forming the second axle 222. Therefore, the vehicle 10 can be rear-wheel drive in electric vehicle mode.

[0061] The control system 208 can be configured to disconnect the torque path 220 between the engine 202 and the first set of wheels (FL, FR) in electric vehicle mode to reduce parasitic pumping energy losses. For example, the clutch 218 can be disengaged. Figure 2 In the example, this means that the first electric traction motor 216 will also be disconnected from the first set of wheels (FL, FR).

[0062] Another advantage of the second electric traction motor 212 is that it can also be configured to operate in hybrid electric vehicle mode, thereby enabling four-wheel drive operation even without a central drive shaft.

[0063] The second electric traction motor 212 can be selectively coupled to one or two wheels RL, RR of the second axle 222. The torque path coupling between the second electric traction motor 212 and one or two wheels RL, RR of the second axle 222 can be achieved via a second clutch 219. The second clutch 219 can be controlled, for example, to open via an actuator under the control of a received signal to disconnect the torque path between the second electric traction motor 212 and one or two wheels (RL, RR) of the second axle 222. In some embodiments, the second clutch 219 may be a dog-tooth clutch.

[0064] Therefore, it will be understood that the second electric traction motor 212 is arranged to be selectively coupled to provide torque to at least one wheel (RL, RR) of an axle of vehicle 100. In some embodiments, vehicle 100 includes another power source arranged to provide torque to at least one wheel (FL, FR) of another axle of vehicle 100. In the illustrated embodiment, the other power source includes another motor 216 in the form of the first electric traction motor 216. In some embodiments, the other power source may include an internal combustion engine 202, which may provide positive torque alone or in combination with the first electric traction motor 216.

[0065] To store power for the electric traction motors 212, 216, system 20 includes a traction battery 200. The traction battery 200 provides the nominal voltage required by the power user, such as the electric traction motors. If the electric traction motors 212, 216 operate at different voltages, a DC-DC converter (not shown) or similar device can be provided to convert the voltage.

[0066] The traction battery 200 can be a high-voltage (HV) battery. Compared to traction batteries for mild HEVs that provide a nominal voltage of tens of volts, a high-voltage traction battery provides a nominal voltage of hundreds of volts. The traction battery 200 can have the voltage and capacity to support sustained electric drive. The traction battery 200 can have a capacity of several kilowatt-hours to maximize range. The capacity can be tens of kilowatt-hours or hundreds of kilowatt-hours.

[0067] Although the traction battery 200 is shown as a single entity, the functionality of the traction battery 200 can be achieved using multiple smaller traction batteries located in different positions on the vehicle 10.

[0068] In some examples, the first electric traction motor 216 and the second electric traction motor 212 can be configured to receive electrical energy from the same traction battery 200. By pairing the first (lightweight) electric traction motor 216 with a high-capacity battery (tens to hundreds of kilowatt-hours), the first electric traction motor 216 can provide the functionality of the method described herein over a sustained period of time rather than in short bursts. In another example, the electric traction motors 212 and 216 can be paired with different traction batteries.

[0069] Finally, the system 20 shown includes one or more inverters. Two inverters 210, 214 are shown, with one inverter corresponding to each electric traction motor 212, 216. In other examples, one inverter or more than two inverters may be provided.

[0070] As can be understood from the above, vehicle 100 can be provided with power torque by a combination of sources. Embodiments of the present invention involve determining which power torque source to use.

[0071] Figure 3 A control system 300 according to an embodiment of the present invention is shown. The control system 300 may be formed by one or more controllers 305. Figure 2 The control system 300 shown includes an electronic controller 305, but it will be understood that this is merely illustrative. Controller 305, or each controller 305, includes a processing unit 310 and a storage unit 320. The processing unit 310 may be one or more electronic processors 310 or processing devices 310, such as a CPU, for executing computer-readable instructions. The storage unit 320 may be one or more storage devices 320. One or more storage devices 320 may store computer-readable instructions executed by at least one processing unit 310.

[0072] The controller 305 includes an input device 330 and an output device 340. The input device 330 is arranged to receive one or more signals 335. The input device 330 may be an electrical input terminal of the controller 305 for receiving one or more electrical signals 335. The output device 340 is arranged to output at least one signal 345. Figure 3 In this configuration, at least one signal 345 is provided to one or both of the second clutch 219 and the second electric traction motor 212 to control coupling with the second torque path, thereby providing torque to one or both wheels of the second axle 222. The output device 340 is the electrical output of the controller 305. The output device 340 can be operated by the processing device 310 to output signal 345 under the control of the processing device 310. Signal 345 can cause the second electric traction motor 212 to "spin faster" or accelerate to a speed suitable for coupling with the second axle 222; that is, remember, the vehicle 100 can be moved by the torque provided by the first electric traction motor 216 and / or the engine 202. Signal 345 can also cause the second clutch 219 to close, coupling the second electric traction motor 212 to the second torque path.

[0073] The electrical input terminals 330 and output terminals 340 of the controller 305 can be provided to / from the vehicle's communication bus or network, such as CANBus or other communication networks. Other communication networks can be implemented, for example, through an Internet Protocol (IP) based network such as Ethernet, or FlexRay or Single-sided patch cord transmission (SENT) protocol, but other protocols may also be used.

[0074] Figure 4 The portion of the controller 305, including the input device 330 and the output device 340 of the system 300, is shown schematically. Figure 4 Inputs 410, 420, 430, 440, 450, 460, and 470 of the input device 330 to the controller 305 are shown, and these inputs form... Figure 3 The signal shown is 335. Figure 4 Modules 510, 520, 530, 540, 550, 560, 570, or functional units, are further illustrated, which can be operatively executed on the processing device 310 of the controller 305. Each of inputs 410, 420, 430, 440, 450, 460, 470 provides information relating to one or more aspects or attributes of the vehicle 100 or its powertrain 20.

[0075] Inputs 410, 420, 430, 440, 450, 460, and 470 may include more than one of the following: speed signal 410, temperature signal 420, fault-derived coupling status request (FDCSR) signal 430, drive mode (DM) signal 440, charge status (SoC) signal 450, and suppression signal 460. These signals provide information or data that, based on the aforementioned information or data, one or more of the modules 510, 520, 530, 540, 550, 560, and 570, determine the desired coupling state. The desired coupling state is the desired coupling of the torque path between the second electric traction motor 212 and one or both wheels RL, RR of the second axle 222 of the vehicle 100, as determined by one or more of the modules 510, 520, 530, 540, 550, 560, and 570.

[0076] One or more speed signals 410 indicate the speed of vehicle 100 (i.e., the speed of vehicle 100 on the ground), wheel speed signals indicate the rotational speed of one or more wheels of the vehicle, and motor speed signals indicate the speed of one or both of the speeds of the first electric traction motor 216 and the second electric traction motor 212.

[0077] Temperature signal 420 indicates one or more of the following: ambient temperature and the temperature of one or more units, or the temperature of a fluid associated with one or more units, particularly a fluid used to cool said units of vehicle 100 (i.e., coolant fluid). For example, the coolant fluid may be the coolant for one or both traction motors 212, 216. In some embodiments, temperature signal 420 includes the temperature associated with one or more units of the powertrain. In some embodiments, the temperature associated with one or more units of the powertrain includes an indication of the temperature of one or both of inverters 210, 214, one or more of electric traction motors 212, 216, the coolant temperature, and the temperature of the traction battery 200. The indication of the temperature of the traction battery 200 may indicate the power capacity of the traction battery 200, which is a function of the temperature and state of charge (SoC) of the traction battery 200. Therefore, in some embodiments, temperature signal 420 may include a signal indicating the power capacity of the traction battery 200, which indicates the temperature.

[0078] The Fault Derivative Coupling State Request Signal (FDCSR) 430 indicates a coupling state request derived when a fault associated with vehicle 100 (e.g., a powertrain-related fault) is determined. For example, if the fault management module (not shown) detects a fault associated with the second clutch 219, the fault management module may request a coupling state of coupling or decoupling in order to control the state of clutch 219 (i.e., open or closed) to manage or resolve the fault. Other faults can be understood to result in a desired coupling state for managing or resolving the fault. In some embodiments, the fault management module 530 may be executed on processing device 310, and therefore the FDCSR signal 430 may be generated internally within controller 305.

[0079] The drive mode signal 440 can indicate the drive mode of the vehicle 100, which can be automatically determined, for example, by an intelligent driving mode or terrain response (TR) determination unit, an autonomous driving controller (e.g., an ADAS system), or selected by the occupants of the vehicle 100. The drive mode signal 440 can indicate the selection of an efficiency-based drive mode (i.e., one providing the lowest fuel and / or energy usage), a four-wheel drive mode (e.g., automatically selecting the number of drive wheels), and the selected drive gear, i.e., neutral, drive (D), reverse (R), etc.

[0080] The Status of Charge (SoC) signal 450 indicates the SoC of the traction battery 200.

[0081] The suppression signal 460 indicates one or more suppression coupling states. For example, the suppression signal 460 may indicate that the coupling state is suppressed to prevent coupling of the second electric traction motor 212 with one or two wheels (RL, RR) of the second axle 222, or that the decoupling state is suppressed to prevent decoupling of the second electric traction motor 212 with one or two wheels (RL, RR) of the second axle 222.

[0082] In some embodiments, inputs 410, 420, 430, 440, 450, 460, and 470 may include a coupling status signal 470, which indicates the actual coupling status of the second electric traction motor 212 with one or both wheels of the second axle 222. In some embodiments, the coupling status signal 470 has both a coupling status and a decoupling status indicating the corresponding coupling. The coupling status signal 470 reports the physical state of the coupling of the second electric traction motor 212 to the second torque path via the second axle 222, and thus indicates the successful coupling or decoupling of the second electric traction motor 212.

[0083] In some embodiments, modules 510, 520, 530, 540, 550, 560, and 570 include a high-speed module 510, a low-speed module 520, a fault management module (FMM) 530, an anti-sensitivity module 540, a suppression module 550, a drive mode module (DMM) 560, and an arbitrator 570. It will be understood that not all modules are present in all embodiments, and therefore embodiments of the present invention may include one or more of the modules described above. Each of the modules will be described below. Each of the high-speed module 510, low-speed module 520, fault management module 530, anti-sensitivity module 540, suppression module 550, and efficiency module 560 present in the relevant embodiments can determine a corresponding desired coupling state. An indication of the desired coupling state is provided to the arbitrator 570 to determine the coupling state of the motor 212 and shaft 222, i.e., the arbitrated coupling state.

[0084] Now take the picture Figure 5 and Figure 6The implementation of the high-speed motor module (HSM) 510 is described. The HSM 510 can be operably executed by the processing device 310 to determine the coupling state of the motor 212 with at least one wheel of the axle 222 based on a speed signal 410 indicating the speed of the vehicle 100. In some embodiments, as will be described, the HSM 510 and the arbitrator 570 are arranged such that the controller 305 outputs a coupling signal 345 based on the speed signal 410 to control the coupling of the second electric traction motor 212 with at least one wheel of the axle 222. The HSM 510 is arranged to decouple the second electric traction motor 212 from at least one wheel of the axle 222 when the vehicle 100 is at high speed, which advantageously prevents the second electric traction motor 212 from rotating at excessively fast speeds that could damage it.

[0085] Figure 5 A method 600 according to an embodiment of the present invention is shown, which can be executed by an HSM 510 executed by a processing device 310 of a controller 305. (Refer to...) Figure 6 Method 600 will be explained. Figure 6 The speed of vehicle 100 over a period of time is shown, as indicated by speed signal 410. Figure 6 The lower half also shows the desired coupling signal 515 output by HSM 510, which represents a request 730, 740 from the desired coupling state determined by speed signal 410 from HSM 510.

[0086] Method 600 includes step 610 of receiving one or more signals (e.g., data representing one or more signals) at HSM 510. In the illustrated embodiment, HSM 510 is arranged to receive a speed signal 410, which, as discussed above, can indicate the speed of vehicle 100. In some embodiments, HSM 510 is arranged to receive a temperature signal 420, as discussed above. In some embodiments, HSM 510 is arranged to receive a SoC signal 460 indicating the state of charge of one or more traction batteries 200 for supplying power to traction motors 212, 216. In some embodiments, HSM 510 may receive a signal indicating the power limit or capacity of the traction battery 200, which, as discussed above, indicates the temperature of the traction battery 200.

[0087] Step 620 includes determining, based on speed signal 410, the desired coupling state between the second electric traction motor 212 and at least one wheel (RL, RR) of the second axle 222. Step 620 includes determining whether the speed of vehicle 100 is equal to or greater than... Figure 6The first high-speed threshold 710 is shown. Therefore, step 620 includes comparing the speed of vehicle 100 with one or more thresholds 710, 720, wherein one or more thresholds 710, 720 include the first high-speed threshold 710. In some embodiments, one or more thresholds 710, 720 include a second high-speed threshold 720. The second high-speed threshold 720 represents a vehicle speed lower than the first high-speed threshold 710. Figure 6 The first high-speed threshold 710 and the second high-speed threshold 720 are shown in the figure.

[0088] If the speed of vehicle 100 is equal to or greater than the first high-speed threshold 710, then method 600 proceeds to step 630. However, if the speed of vehicle 100 is less than the first high-speed threshold 710, then method 600 proceeds to step 640.

[0089] exist Figure 6 In the example, method 600 proceeds to step 640 before time t1. Before time t1, it will be understood that vehicle 100 is generally accelerating, which can be caused by the positive torque applied by the first electric traction motor 216 and / or engine 202 and the second electric traction motor 212 coupled to the second torque path via the second shaft 222.

[0090] In step 630, the desired coupling state is determined to be decoupled based on the speed signal 410 indicating that the vehicle speed is equal to or greater than the first high-speed threshold 710. In step 630, HSM 510 may output an indication 515 of the desired decoupled coupling state to arbitrator 570, indicating a request to decouple the second electric traction motor 212 from the second shaft 222 740. The indication 515 of the desired decoupled coupling state 740 may be referred to as a high-speed coupling state request 515, 740. In some embodiments, as will be explained, arbitrator 570 may arbitrate among multiple desired coupling state requests. In the absence of any other competing requests from other modules, arbitrator 570 is arranged to output the high-speed coupling state request 515 for decoupling state 740 as an output signal 345 via output device 340. In some embodiments, the high-speed coupling state request 515 may be provided directly from HSM 510 to output device 340 of controller 305.

[0091] After time t1, i.e., once the speed of vehicle 100 exceeds the first high-speed threshold 710, it is determined that the second electric traction motor 212 needs to be decoupled. The continued coupling of the second electric traction motor 212 to the wheels of vehicle 100 causes the second electric traction motor 212 to exceed a predetermined speed. The predetermined speed could be a motor speed of 12,000 rpm, but it will be understood that other predetermined speeds can be selected. The predetermined speed could correspond to 140 km / h. -1The vehicle speed, however, will be understood to depend on the gearing mechanism between the second electric traction motor 212 and the wheels of the vehicle 100, and the wheel diameter. Furthermore, in some embodiments, as will be referred to... Figure 7 As explained, the vehicle speed corresponding to the rotational speed of the first high-speed threshold 710 and the second electric traction motor 212 can be determined based on the temperature.

[0092] The output device 340 of the controller 305 is arranged to output coupling signals 345, 730, 740 according to the desired coupling state of decoupling, the coupling signals indicating a request to decouple the second electric traction motor 212 from at least one wheel of the second axle 222 740.

[0093] If the speed of vehicle 100 is less than the first high-speed threshold 710 in step 620, the method proceeds to step 640. In step 640, it is determined whether the speed of vehicle 100 is less than or equal to the second high-speed threshold 720. If the speed of vehicle 100 is less than or equal to the second high-speed threshold 720, the method proceeds to step 660.

[0094] In step 660, HSM 510 is configured not to request the desired coupling state of the second motor 212. HSM 510 outputs a coupling state request to arbitrator 570, or as... Figure 5 The arbitrator 570 outputs a "no request" signal 730, which indicates that the HSM 510 does not request a specific coupling state between the second electric traction motor 212 and one or more wheels of the second axle 222. Therefore, in Figure 6 Before time t1, HSM 510 outputs a no-request signal 730 to arbitrator 570, or in other embodiments, it may not output a signal to arbitrator 570. Arbitrator 570 may have a default coupling state. The default coupling state may be coupled, that is, coupling the second electric traction motor 212 to the torque path of the second shaft 222. Therefore, when arbitrator 570 receives the "no-request" signal 730 or the no-request signal, arbitrator 570 may output the determined coupling request via output device 340.

[0095] In some embodiments, HSM 510 is arranged to output a coupling signal 345 indicating a request to mechanically couple the second electric traction motor 212 to at least one wheel of the second axle 222. It will be understood that in some embodiments, HSM 510 may request a default coupling state when speed signal 410 indicates a low vehicle speed.

[0096] In some embodiments, HSM 510 can apply a hysteresis to the speed signal 410 to determine the coupling state. That is, a decoupled coupling state can be determined for a vehicle speed greater than the vehicle speed at which the second electric traction motor 212 is recoupled to the torque path via the second axle 222, i.e., above a second high-speed threshold 720. Advantageously, this helps prevent “oscillations” or “flickers” between the decoupled and coupled states when the vehicle speed varies around (above and below) the first high-speed threshold 710. In some embodiments, the use of the second high-speed threshold 720 provides hysteresis. Figure 6 It is understandable that between time t1 and time t2, the vehicle decelerates from its peak speed, causing the speed signal 410 to drop below the first high-speed threshold 710. According to... Figure 6 The lower half can be understood as follows: when the speed of vehicle 100 drops below the first high-speed threshold 710, it will not immediately output a "no request" signal 730.

[0097] Conversely, in the region between the first high-speed threshold 710 and the second high-speed threshold 720, the decoupling 740 remains in a coupled state until the vehicle speed drops below the second high-speed threshold 720. When the vehicle speed is between the first high-speed threshold 710 and the second high-speed threshold 720, step 650 is reached, in which the desired coupling state is determined based on the speed signal 410 according to the most recently intersecting threshold between the first high-speed threshold 710 and the second high-speed threshold 720. Therefore, before time t2, when the speed signal 410 is below the first high-speed threshold 710, in step 650, the coupling state is determined to be decoupled based on the most recently intersecting threshold 710. Therefore, the method moves to step 630. Similarly, before time t1, when the speed signal 410 is above the second high-speed threshold 720, the method moves to step 660, where the "no request" output signal 730 is maintained, such that in the example embodiment, the arbitrator 570 determines the coupling state to be coupled.

[0098] Therefore, it can be understood that the embodiments of the present invention select the coupling of the second electric traction motor 212 according to the speed of the vehicle 100.

[0099] Figure 7 The speed (RPM) of the electric motor, i.e. the speed of the second electric traction motor 121, and the temperature are shown according to an embodiment of the present invention. Figure 7A first high-speed threshold 710 is shown, which, according to some embodiments of the invention, varies with temperature. As described above, in some embodiments of the invention, controller 305 receives a temperature signal 420. In some embodiments, the first high-speed threshold 710 adopts a first value 710 between a first temperature 740 and a second temperature 750. The first temperature 740 (below which one or both of the first high-speed threshold 710 and the second high-speed threshold 720 decreases) may correspond to a cold temperature, such as a temperature below 0°C (e.g., -5°C), but it will be appreciated that other temperatures can be selected. It will be understood that, although not shown, the second high-speed threshold 720 may follow the first high-speed threshold 710.

[0100] Below the first temperature 740, in some embodiments, the first high-speed threshold 710 is reduced, i.e., reduced to a value 810, such that the coupling state of the second electric traction motor 212 is determined to be decoupled at lower speeds, as shown. In some embodiments, one or both of the first high-speed threshold 710 and the second high-speed threshold 720 may be reduced proportionally to the temperature in one or more temperature regions. Advantageously, the reduction of the first high-speed thresholds 710, 810 allows, for example, a change in the coolant of the second electric traction motor 212 or a reduction in the viscosity of the fluid associated with the second torque path via the second shaft 222, so that the rotation of the motor 212 can consume more energy, and thus low-speed decoupling is more efficient. Figure 7 In the illustrated embodiment, the first high-speed thresholds 710 and 810 are arranged to decrease according to temperature within a first temperature range 740, 730. The temperature range can be between -10°C and -20°C, but other temperature ranges may also be selected. In other embodiments, the first high-speed threshold 710 may decrease instantaneously; however, advantageously, a gradual change may be less noticeable to the occupants of vehicle 100. Below the third temperature 730, the first high-speed threshold 810 corresponds to a minimum threshold speed 810.

[0101] Similarly, in some embodiments, above the second temperature 750, the first high-speed threshold 710 is arranged to decrease according to temperature within the second temperature range 750, 760 toward the fourth temperature 760. Above the fourth temperature 760, in some embodiments, the first high-speed threshold 710 adopts a constant value 820, which can be related to... Figure 7 The minimum threshold speed 810 shown is different, but in other embodiments, the two speeds 810, 820 can be equal. Advantageously, the reduction of the first high-speed threshold 710, 820 at higher speeds can reduce cooling problems associated with the second electric traction motor 212. The temperature 750 can be at least 25°C or at least 35°C, for example, in some embodiments, a temperature between 50°C and 60°C.

[0102] As described above, in some embodiments, controller 305 is arranged to receive SoC signal 450. In some embodiments, one or both of a first high-speed threshold 710 and a second high-speed threshold 720 are determined based on the SoC of traction battery 200. As described above, in some embodiments, arbitrator 570 may be arranged to implement a default coupled state in the absence of a decoupling state request from HSM 510. In this way, HSM 510 and arbitrator 570 operate to decouple the second electric traction motor 212 when the vehicle 100 speed is above the first high-speed threshold 710 and to couple when the vehicle 100 speed is below the second high-speed threshold 720. In some embodiments, in order to couple the second electric traction motor 212 to the second axle, the second electric traction motor 212 needs to “spin-accelerate” or accelerate to a speed substantially at the rear axle 222 before the second clutch 219 can be closed to couple the second electric traction motor 212 to the axle 222. It is understood that the second electric traction motor 212 accelerates the consumption of energy from the traction battery 200. When the vehicle 100 operates using the traction battery 200 with a low SoC, one or both of the first high-speed threshold 710 and the second high-speed threshold 720 can be reduced according to the SoC. Advantageously, when the traction battery 200 has a lower SoC, by reducing the speed corresponding to one or both of the first high-speed threshold 710 and the second high-speed threshold 720, the second electric traction motor 212 only needs to "spin-accelerate" to a lower speed to recouple to the second shaft 222, thus requiring less energy consumption.

[0103] Now refer to Figure 8 and Figure 9 The implementation of the low-speed module (LSM) 520 is explained. In operation, the LSM 520 can be executed by the processing device 310 to determine the coupling state of the motor 212 with at least one wheel of the second axle 222 based on a speed signal 410 indicating the speed of the vehicle 100. In some embodiments, as will be explained, the LSM 510 and the arbitrator 570 are arranged to cause the controller 305 to output a coupling signal 345 to control the coupling of the motor 212 with at least one wheel of the second axle 222 based on the speed signal 410. As will be explained, the LSM 520 is arranged to couple the motor 212 with at least one wheel of the axle 222 at low speeds, which advantageously enables the motor 212 to provide power torque to the vehicle at low speeds (particularly from rest). Furthermore, as will be explained, the LSM 520 is arranged to control the coupling of the motor to avoid or reduce characteristics that may be obviously undesirable to the occupants of the vehicle 100.

[0104] Figure 9A method 1000 according to an embodiment of the present invention is shown, which can be executed by an LSM 520 executed by a processing device 310 via a controller 305. (Refer to...) Figure 8 Let's explain method 1000. Figure 8 This indicates the vehicle speed over a period of time, as indicated by speed signal 410. Figure 8 The lower part also shows the desired coupling signal 525 output by LSM 520, which represents a request 730, 750 from LSM 520 for the desired coupling state determined by speed signal 410.

[0105] Method 1000 includes step 1010: receiving one or more signals, such as data representing one or more signals, at LSM 520. In the illustrated embodiment, LSM 520 is arranged to receive a speed signal 410 indicating the speed of vehicle 100.

[0106] Step 1020 includes determining the desired coupling state between the second electric traction motor 212 and at least one wheel (RL, RR) of the second axle 222 based on the speed signal 410. Step 1020 includes determining whether the speed of the vehicle 100 is equal to or less than a first low speed threshold (LST) 910. Therefore, step 1020 includes comparing the speed of the vehicle 100 with one or more thresholds 910, 920, one or more of which include the first LST 910. In some embodiments, such as Figure 8 As shown, one or more low-speed thresholds 910, 920 include a second LST 920. The second LST 920 represents a vehicle speed greater than the first LST 910. Figure 8 The first LST 910 and the second LST 920 are shown.

[0107] In step 1030, a desired coupling state is determined as coupling based on a speed signal 410 indicating that the vehicle speed is equal to or lower than the first LST 910. In step 1030, the LSM 520 may output an indication 525 of the desired coupling state to the arbitrator 570, indicating a request to couple the second electric traction motor 212 750 to the second axle 222. The indication 525 of the desired coupling state 750 may be referred to as a low-speed coupling state request 525, 750. In some embodiments, the arbitrator 570 may arbitrate among multiple requests for desired coupling states. In the absence of any other competing requests from other modules, the arbitrator 570 is arranged to output the low-speed coupling state request 525 of coupling state 750 as an output signal 345 via output device 340. In some embodiments, the low-speed coupling state requests 525, 750 may be provided directly from the LSM 520 to the output device 340 of the controller 305.

[0108] Reference Figure 8 After time t3, i.e., once the speed of vehicle 100 is equal to or lower than the first LST 910, it is determined that the second electric traction motor 212 is to be coupled. For example, it can be envisioned that vehicle 100 is about to stop, and the torque from the second electric traction motor 212 will be useful, for example, for starting from a standstill. The predetermined vehicle speed corresponding to the first LST 910 could be 10 km / h. -1 The vehicle speed can be specified, but it should be understood that other vehicle speeds can be selected. In some embodiments, the vehicle speed corresponding to the first LST 910 can be selected or determined based on the deceleration rate of the vehicle 100, which can be determined based on the rate of change of the speed signal 410. In the presence of a large deceleration (i.e., above a deceleration threshold), the vehicle speed corresponding to the first LST 910 can be increased to advantageously enable coupling of the second electric traction motor 212 before the vehicle 100 comes to a stop.

[0109] The output device 340 of the controller 305 is arranged to output a coupling signal 345,750 according to the desired coupling state as performed in step 1030, the coupling signal 345,750 indicating a request to couple the second electric traction motor 212 750 to at least one wheel of the second axle 222.

[0110] In some cases, due to the default coupling state shown in Table 1 below, the output will be affected by the vehicle speed decrease across LST 910. Figure 8 The coupling request 750 shown will have no practical effect (state change) because the default coupling state of the second electric traction motor 212 is already coupled to the second axle 222. However, in some cases, when the vehicle speed decreases across LST 910, the second electric traction motor 212 will decouple from the second axle 222. In this case, the arbitrator 570 can determine the arbitrated coupling state relative to LST 910 based on the reason for the second electric traction motor 212 disconnection. If the arbitrated coupling state is decoupled due to a high-priority reason such as a fault when the vehicle speed is above LST 910, the arbitrator 570 will not respond to the coupling request 750 from LSM 520 to change the arbitrated coupling state to coupled. However, if the reason for the decoupling state is a lower-priority reason such as a priority reason, the arbitrator 570 may respond to the coupling request 750 from LSM 520 to change the arbitrated coupling state to coupled.

[0111] If, in step 1020, the speed of vehicle 100 is greater than the first LST 910, the method proceeds to step 1040. In step 1040, it is determined whether the speed of vehicle 100 is greater than or equal to the second LST 920. If the speed of vehicle 100 is greater than or equal to the second LST 920, the method proceeds to step 1060.

[0112] In step 1060, LSM 520 is configured not to request the desired coupling state of the second motor 212. LSM 520 outputs a request for the coupling state to arbitrator 570, and as... Figure 8 As shown, a "no request" signal 730 can be output to the arbitrator 570, wherein the no request signal 730 indicates that the LSM 520 does not request a specific coupling state between the second electric traction motor 212 and one or more wheels of the second axle 222. Therefore, in Figure 8 Before time t3, LSM 520 outputs a no-request signal 730 to arbitrator 570, or in other embodiments, it may not output a signal to arbitrator 570. Arbitrator 570 may have a default coupling state. The default coupling state may be coupling, that is, coupling the second electric traction motor 212 to the torque path of the second shaft 222. Therefore, when arbitrator 570 receives a "no-request" signal 730 or does not receive a request signal, arbitrator 570 may output a determined coupling request via output device 340.

[0113] In some embodiments, LSM 520 is arranged to output a coupling signal 345 indicating a request to couple the second electric traction motor 212 to at least one wheel of the second axle 222. It should be understood that in some embodiments, LSM 520 may request a default coupling state when speed signal 410 indicates a low vehicle speed, i.e., below the first LST 910.

[0114] In some embodiments, LSM 520 can apply a hysteresis to speed signal 410 to determine the coupling state. That is, for vehicle speeds greater than the second electric traction motor 212 determined to be coupled to the torque path via the second axle 222 (i.e., greater than the first LST 910), the coupling state can be determined. Advantageously, this helps prevent “swinging” or “flickering” between decoupled and coupled states when the vehicle speed changes near (above and below) the first LST 910. In some embodiments, the hysteresis is provided using a second LST 920. Figure 8 It is understandable that between time t3 and time t4, the vehicle accelerates from its minimum speed, causing speed signal 410 to exceed the first LST910 for a period of time before time t4. (As from...) Figure 8The lower part can be understood to not immediately output a "no request" signal 730 when the speed of vehicle 100 exceeds the first LST 910, that is, to maintain coupling 750.

[0115] Conversely, in the region between the first LST 910 and the second LST 920, the coupling state of coupling 750 is maintained until the vehicle speed exceeds the second LST 920 at time t4. In step 1050, which is reached when the vehicle speed is between the first LST 910 and the second LST 920, the desired coupling state is determined based on the most recent intersection of the first LST 910 and the second LST 920 according to the speed signal 410. Therefore, before time t4, when the speed signal 410 is lower than the second LST 920, in step 1050, the coupling state is determined as a coupling state based on the most recent intersection with the first LST 910. Similarly, just before time t3, when the speed signal 410 is higher than the first LST 920, the "no request" output signal 730 is maintained because the threshold for the most recent intersection is the second LST 920.

[0116] As from Figure 8 Understandably, some implementations of LSM 520 include a third LST 930. When the vehicle speed 410 is equal to or less than the third LST 930, if the motor 212 is not successfully coupled to the second torque path via the second shaft 222, the coupling of the motor 212 is suppressed. The third LST 930 may correspond to, for example, 5 km / h. -1 The speed is [specific speed], but it should be understood that other speeds can be chosen.

[0117] In some embodiments, LSM 520 is arranged to receive a signal indicating the coupling state 470 of the second electric traction motor 212 with at least one wheel of axle 222. Signal 470 reports whether the second electric traction motor 212 has been successfully coupled to at least one wheel of axle 222. In some cases, the coupling state can be determined to be coupled and a corresponding request can be output by controller 305. However, due to electrical and / or mechanical reasons, it may not be possible (at least not immediately) to couple the motor 212 to the second torque path. For example, the second clutch 219 may not have successfully engaged the drive output of the motor 212 to axle 222. In particular, it may be difficult to successfully couple the motor 212 when the vehicle is moving slowly or has become stationary. Furthermore, attempts to couple the motor 212 to the axle may be more noticeable to the occupants of vehicle 100 at low speeds, for example, in the form of noise and / or vibration, and may cause damage if attempted while stationary. The use of a third LST 930 can mitigate such risks.

[0118] In some embodiments, LSM 520 determines the coupling suppression state. In some embodiments, when speed signal 410 indicates that the vehicle speed is equal to or lower than the third LST 930, LSM 520 outputs a coupling suppression signal 526 in the coupling suppression state. When the vehicle speed is lower than the third LST 930 and coupling state signal 470 indicates that the second electric traction motor 212 is decoupled from the second axle 222, that is, when successful coupling caused by a vehicle speed lower than the first LST 910 has not yet occurred, LSM 520 may output the coupling suppression signal 526.

[0119] In some implementations, LSM 520 can apply a hysteresis to speed signal 410 to determine a coupling suppression state. That is, for vehicle speeds greater than the third LST 930, a coupling suppression state can be determined. Advantageously, this helps prevent "swinging" or "flickering" between decoupled and coupled states when the vehicle speed varies around (above and below) the third LST 930. In some implementations, using... Figure 9 The fourth LST 950 shown provides hysteresis. The fourth LST 950 defines the maximum speed of the coupling suppression region 940, which defines the coupling suppression state. The third LST 930 and the fourth LST 950 operate as described above with respect to the first LST 910, the second LST 920, and the speed signal 410.

[0120] Some embodiments of the present invention include a fault management module (FMM) 530. The FMM 530 is arranged to determine a desired coupling state between the second electric traction motor 212 and at least one wheel (RL, RR) of the second axle 222 based on the detection or determination of one or more faults associated with the vehicle 100. The coupling state determined by the FMM 530 is selected to manage or mitigate the faults associated with the vehicle 100. For example, the FMM 530 may receive a temperature signal 420, which indicates the inverter temperature associated with the second electric traction motor 212. If the temperature signal 420 indicates that the inverter has a high temperature (above a predetermined threshold), the FMM 530 is arranged to determine the coupling state as a decoupling state, allowing the second electric traction motor 212 to stop operating, thereby allowing the inverter to cool down for a period of time. In another example, the FMM 530 is arranged to receive a coupling state signal 470 as discussed above. The coupling state signal 470 may indicate a failure to decouple the second electric traction motor 212 from the axle. Therefore, the FMM 530 can use this as a basis to determine the coupling state as coupled, thereby reducing problems associated with problematic decoupling states. The FMM 530 is arranged to output a Fault Derivative Coupling State Request (FDCSR) signal 535 based on one or more received signals indicating fault states associated with vehicle 100. The FDCSR signal 535 indicates a coupling state request determined by the FMM 530 in response to one or more faults or undesirable conditions or parameters associated with the vehicle. Figure 4 As shown, in some embodiments, the FDCSR signal 535 is received by the arbitrator 570.

[0121] In some embodiments, FMM 530 is arranged to manage retrying the change of coupling state of the second electric traction motor 212, i.e., further attempts, in the event that the change of coupling state has failed. Specifically, in some embodiments, FMM 530 is arranged to control the output device 340 of controller 305 to output a signal 345 indicating a retry for the change of coupling state of the second electric traction motor 212, as will be explained, i.e., requesting further attempts.

[0122] Figure 11 A method 1200 according to an embodiment of the present invention is shown. Method 1200 is a method for managing retrying changes to the coupling state of a second electric traction motor 212.

[0123] In step 1210, the coupling state of the second electric traction motor 212 is determined. The coupling state can be determined by one of modules 510 to 560 and a subsequent coupling state request signal received at arbitrator 570, or, for example, by arbitrator 570 in the absence of a default coupling state without any request from modules 510 to 560.

[0124] In step 1220, the controller 305 outputs a coupling state request signal 345 via the output device 340 to request a determined coupling state. For example, the coupling state request may be a request for either a coupling state or a decoupling state between the second electric traction motor 212 and the second shaft 222.

[0125] In step 1230, FMM 530 is configured to determine whether a failure has occurred in changing the coupling state of the second electric traction motor 212 and the second axle 222. As described above, the coupling state signal 470 indicates the actual coupling state of one or both wheels of the second electric traction motor 212 and the second axle 222. Therefore, FMM 530 can determine whether a failure has occurred based on the coupling state signal 470, i.e., whether the actual coupling state reflects the requested coupling state. Step 1230 may be performed after a delay to allow the change in coupling state to be implemented, for example, the second clutch 219 to open or close. If the change in coupling state is successful, the method returns to step 1210. However, if the change is unsuccessful, i.e., as indicated by the coupling state signal 470, a failure has occurred in changing the coupling state of the second electric traction motor 212, the method moves to step 1240.

[0126] In step 1240, the speed of vehicle 100 is determined. Step 1240 includes receiving a speed signal 410 indicating the speed of vehicle 100. As will be explained, based on the speed signal 410, the output device 340 of control controller 305 is executed to output a coupling signal 345 indicating a retry for changing the coupling state.

[0127] In some embodiments, FMM 530 is arranged to output a delay to control output device 340 of a coupling signal 345 indicating a retry to change the coupling state, based on a speed signal 410 indicating that the speed of vehicle 100 is at least a predetermined minimum speed. The predetermined minimum speed may be, for example, substantially greater than 0 km / h. -1 The speed. Other predetermined minimum speeds could be, for example, 5 km / h. -1However, it is understood that other minimum speeds can be chosen. Advantageously, preventing retrying of changes in coupling state, particularly changes from decoupling to coupling, at excessively low vehicle speeds can prevent retrying of engagement of the second electric traction motor 212 with the shaft from being noticeable to vehicle occupants. For example (but not exclusively), in the case where the second clutch 219 is a claw clutch, attempting to retry at low vehicle speeds could result in noise and / or vibration.

[0128] In some embodiments, the FMM 530 is arranged to delay the output of a retry signal 345 indicating a change in coupling state to the control output device 345 based on a speed signal indicating that the speed of the vehicle 100 is less than the maximum speed. The maximum speed can be, for example, up to 50 km / h. -1 or up to 30km / h -1 or up to 20km / h -1 However, other maximum speeds can be selected. As mentioned above, in order to couple the second electric traction motor 212 to the second shaft 222, it may be necessary to "speed up" or accelerate the motor 212 to approximately the rotational speed of the shaft 222. Advantageously, the maximum speed avoids or reduces the power required to couple the motor 212 to the shaft 222. Furthermore, changing from the decoupled state to the coupled state at a vehicle speed below the maximum speed avoids attempting to couple the second electric traction motor 212 to the shaft during large deceleration periods (i.e., during severe braking or other deceleration of the vehicle 100) when it may be difficult to match the rotational speed of the second electric traction motor 212 to the shaft. Therefore, the FMM 530 outputs a coupling signal 345 indicating a delay for retrying the change of coupling state to the control output device 345 based on the speed signal 410 indicating that the vehicle speed is less than or equal to the predetermined maximum speed.

[0129] In step 1250, when FMM 530 determines that the speed of vehicle 100 is higher than the minimum speed or higher than the minimum speed but lower than the maximum speed considered in step 1240, FMM 530 is arranged to output a signal 535 indicating a request to retry changing the coupling state. Signal 535 may be a further request to change the coupling state, such as a request for either a coupled or decoupled state. The request may be received by arbitrator 570, which outputs a corresponding request or signal 345 via output device 340 to induce a retry to change the coupling state. Once a retry to change the state is requested, the method returns to step 1230, where the success of the retry is considered.

[0130] In some implementations, for each iteration of step 1250, a counter is maintained to track the number of retries that change the coupling state. In some implementations, FMM 350 is configured to attempt retries up to a predetermined maximum number. That is, step 1250 is performed up to the maximum number. In some implementations, the maximum number can be 5, 3, or 2. Advantageously, the maximum number of retries can prevent an excessive number of retries to avoid damaging system 300 and / or reduce the power wasted by “speeding up” the second electric traction motor 212 to attempt further retries.

[0131] Some embodiments of the present invention include an anti-fussiness module (AFM) 540. The AFM 540 is arranged to control changes in the coupling state of the second electric traction motor 212. Specifically, the AFM 540 is arranged to control the timing of changes in the coupling state of the second electric traction motor 212. The AFM 540 ensures that changes in the coupling state of the second electric traction motor 212 do not occur frequently, i.e., at least a predetermined time period is provided between changes in the coupling state of the second electric traction motor 212. The AFM 540 in Figure 4 The arbitrator 570 is shown as part of the arbitrator 570. However, it will be appreciated that the AFM 540 may be located elsewhere, i.e., other structures are conceivable.

[0132] Figure 12 A method 1300 according to an embodiment of the present invention is shown. Method 1300 is a method for controlling the change of the coupling state of a second electric traction motor 212 according to an embodiment of the present invention. Method 1300 can be executed by AF module 540.

[0133] In step 1310 of the method, the coupling state of the second electric traction motor 212 via the second axle 222 to the second torque path is determined. In other words, step 1310 includes determining whether the second electric traction motor 212 is coupled to one or more wheels (RR, RL) of the second axle 222 of the vehicle 100. This determination is performed based on at least one attribute signal, such as a speed signal 410 or a drive mode signal 440 indicating the speed of the vehicle 100. As described above, the coupling state of the second electric traction motor 212 can be determined by one of modules 510, 520, 530, 550, and 560, as well as a corresponding signal or request provided to the arbitrator 570. For example, HSM 510 can provide a request to decouple the second electric traction motor 212 from the rear axle 222, while FMM 530 can provide a request to couple the second electric traction motor 212 to the rear axle 222. Therefore, requests for various coupling states can originate from different modules. Advantageously, the AF module 540 is arranged to prevent frequent changes in the coupling state of the second electric traction motor 212, so as to avoid such changes being noticeable to the occupants of the vehicle 100. Step 1310 may include receiving one or more requests for coupling state at the arbitrator 570, specifically the AFM 540.

[0134] Step 1320 includes determining whether a predetermined time period has elapsed since the most recent or most recent change in the coupling state of the second electric traction motor 212. The predetermined time period may be the period since the controller 305 output the most recent request for a change in the coupling state, or the period since the coupling state signal 470 reported a successful change in the coupling state. The predetermined time period may be, for example, at least 5 seconds, at least 10 seconds, at least 20 seconds, or at least 30 seconds. It should be understood that other time periods are conceivable. If the predetermined time period has elapsed, method 1300 proceeds to step 1340.

[0135] If the predetermined time period has not yet elapsed, the method proceeds to step 1330, in which AFM 540 is arranged to wait, i.e., the output signal 345 indicating a request to change the coupling state to the output device 340 of the control controller 305 is postponed until the predetermined time period since the most recent change in the coupling state has elapsed. AFM 540 may buffer incoming or received coupling state requests from modules 510, 520, 530, 550, and 560 until the predetermined time period has elapsed. It should be understood that the desired coupling state can be continuously re-evaluated during the predetermined time period. Therefore, when the predetermined time period has elapsed, the coupling state can be determined based on the most recently received coupling state request instead of implementing the first buffered request. Advantageously, this ensures that the coupling state requested after the predetermined time period has elapsed reflects the most recent attributes of vehicle 100. When the predetermined time period has elapsed, the method proceeds to step 1340.

[0136] In step 1340, the AF module 540 is arranged to control the output device 340 of the controller 305 to output a coupling request signal 345 to control the coupling of the second electric traction motor 212 with the rear axle 222. In some embodiments, as will be explained, the suppression module provides a signal 575 indicating an arbitrated coupling request.

[0137] Some embodiments of the invention include a suppression module 550. The suppression module 550 is arranged to control changes in the coupling state of the second electric traction motor 212. Specifically, the suppression module 550 is arranged to suppress one or more coupling states of the second electric traction motor 212 with the rear axle 222. Suppression of coupling states prevents the controller 305 from requesting the suppression of a coupling state. The suppression module 550 in… Figure 4 The diagram shows the formation portion of the arbitrator 570. However, it will be appreciated that the suppression module 550 may be located elsewhere; that is, other structures are conceivable.

[0138] Suppression module 550 is arranged to receive suppression signal 460. The suppression signal indicates one or more coupling states of the second electric traction motor 212 and the rear axle 222 that are prohibited or suppressed. Suppression signal 460 can indicate one of the coupling and decoupling states of the second electric traction motor 212 and the rear axle 222. Although suppression signal 460 is shown as a single signal, it should be understood that in other embodiments, a corresponding signal can be provided for each of the coupling and decoupling coupling states to indicate whether each state is suppressed. As described below, the suppression module is arranged to output a coupling state suppression signal 555 to the arbitrator indicating a request for a coupling state. In particular, coupling state suppression signal 555 indicates a request for a coupling state when it is not suppressed, thereby further indicating which coupling states are not suppressed.

[0139] Figure 13 A method 1400 according to an embodiment of the present invention is shown. Method 1400 is a method for controlling the change of the coupling state of a second electric traction motor 212 according to an embodiment of the present invention. Method 1400 can be executed by a suppression module 550.

[0140] In step 1410 of the method, the coupling state of the second electric traction motor 212 via the second axle 222 to the second torque path is determined. In other words, step 1410 includes determining whether the second electric traction motor 212 is coupled to one or more wheels (RR, RL) of the second axle 222 of the vehicle 100. This determination can be performed based on a determination that the expected amount of power required to accelerate the second electric traction motor 212 to the speed of the rear axle is equivalent to the amount of power available from the traction battery 200. As described above, the coupling state of the second electric traction motor 212 can be determined by one of modules 510, 520, 530, 560 and a corresponding signal or request provided to the arbitrator 570. For example, HSM 510 can provide a request to decouple the second electric traction motor 212 from the rear axle 222, while FMM 530 can provide a request to couple the second electric traction motor 212 to the rear axle 222. Therefore, requests for various coupling states can originate from different modules. Advantageously, the suppression module 550 is arranged to prevent the selection of a coupling state for the second electric traction motor 212, for example, to avoid a state associated with a fault. For example, when a fault is determined to prevent the second electric traction motor 212 from coupling to the rear axle 222, the suppression module 550 can suppress the coupling state to avoid selecting the coupling state. Similarly, in some embodiments, one or more coupling states can be suppressed based on one or more of the power limitations or capacity limitations of the traction battery 200. For example, if it is determined that the capacity of the traction battery 200 provides sufficient power to accelerate the second electric traction motor 212 to couple to the rear axle 222, the coupling state can be suppressed in step 1410.

[0141] Step 1410 may include receiving one or more requests for a coupling state at the arbitrator 570, and particularly at the suppression module 550. As explained below, the arbitrator 570 may determine the arbitrated coupling state based on the received requests.

[0142] In step 1420, it is determined whether the determined coupling state is suppressed. The determined coupling state may be an arbitrated coupling state determined by arbitrator 570. Step 1420 includes comparing the determined coupling state with one or more suppressed coupling states (e.g., a suppression signal 460 indicating that the coupling state is suppressed). If the determined coupling state differs from the coupling state indicated by the suppression signal, or if no coupling state is indicated as suppressed, the method proceeds to step 1430. However, if the suppression signal 460 indicates that the determined coupling state is suppressed, the method returns to step 1410. In other words, method 1400 prevents the output of a request for a suppressed coupling state in step 1430.

[0143] In step 1430, the suppression module 550 is arranged to control the output device 340 of the controller 305 to output a coupling request signal 345 to control the coupling of the second electric traction motor 212 with the rear axle 222. That is, when the suppression signal 460 does not indicate that the determined coupling state is suppressed, the controller 305 outputs a request for the determined coupling state.

[0144] Some embodiments of the invention include a drive mode module (DMM) 560. The DMM 560 is arranged to determine the coupling state of the second electric traction motor 212 based on the drive mode of the vehicle 100. The drive mode of the vehicle 100 is indicated by a drive mode signal 440. For example, the drive mode of the vehicle 100 may be selected by the driver or passenger of the vehicle 100, or may be determined at least in part by a module or system of the vehicle 100, such as a terrain response (TR) module, which adaptively selects a drive mode, such as its traction control mode, which includes one or more settings of the vehicle, and particularly its powertrain. The drive mode may include, for example, a drive selection setting of the powertrain, including the vehicle's drive mode, including one of forward, reverse, or neutral in the case of gear selection in an automatic or manual transmission. The drive mode may include selecting one of a sport drive mode, a normal drive mode, or an economy drive mode, wherein settings of one or more of the vehicle 100's engine, first electric motor and / or second electric motor, suspension, etc., may be adjusted accordingly. Data indicating the selected drive mode is provided by the drive mode signal.

[0145] Figure 14 Method 1500 according to an embodiment of the present invention is shown. Method 1300 is a method for controlling the change of the coupling state of a second electric traction motor 212 according to an embodiment of the present invention. Some steps of method 1500 can be performed by DMM 560.

[0146] In step 1510, an attribute-based coupling state between the second electric traction motor 212 and the second axle 222 is determined. This determination is performed based on at least one attribute signal, such as a speed signal 410 indicating vehicle speed. As described above, the coupling state of the second electric traction motor 212 can be determined by one of modules 510, 520, 530, and 560, as well as a corresponding signal or request provided to the arbitrator 570. For example, HSM 510 can provide a request to decouple the second electric traction motor 212 from the rear axle 222, while FMM 530 can provide a request to couple the second electric traction motor 212 to the rear axle 222. Therefore, requests for various coupling states can originate from different modules. Step 1510 can be performed by one or more of HSM 510, LSM 520, and FMM 530. Step 1510 can be performed based on signals 515, 525, and 535 other than the drive mode signal 440. One or more signals indicating the determined coupling state are provided to the arbitrator 570. The one or more coupling states determined in step 1510 may be collectively referred to as the first coupling state of the second electric traction motor 212.

[0147] In step 1520, the coupling state between the second electric traction motor 212 and the second shaft 222 based on the drive mode is determined. Step 1520 is determined according to the drive mode signal 440.

[0148] In one example, the drive mode signal 440 may indicate the selected vehicle drive mode, including selecting an efficiency-based drive mode. Selecting an efficiency-based drive mode provides improved efficiency for vehicle 100, i.e., reduced energy consumption, such as reduced performance expenditure of vehicle 100. Efficiency could be improved fuel consumption supplied to engine 202 or reduced electrical energy consumed by electric motors 212, 216. The drive mode signal 440 indicating the selection of the efficiency-based drive mode can be manual or automatic. Similarly, in another example, the drive mode signal may indicate the selection of neutral gear for vehicle 100.

[0149] DMM 560 is configured to determine, for example, one of coupling or decoupling, the coupling state between the second electric traction motor 212 and the rear axle 222 based on the drive mode signal 440. A signal 565 indicating the coupling state based on the drive mode is provided to arbitrator 570. The coupling state based on the drive mode can be referred to as the second coupling state of the second electric traction motor 212. Therefore, the coupling state determined in step 1520 can be decoupling.

[0150] In another example, the drive mode signal 440 may instruct the driver to select, or for example, automatically select, a drive mode via the terrain response module, such as requesting four-wheel drive of vehicle 100 that requires coupling the second electric traction motor 212 to power the rear axle 222. Therefore, the coupling state can be determined as coupled in step 1520.

[0151] In step 1530, it is determined whether the first coupling state and the second coupling state are the same, that is, they are the same. In other words, is the first coupling state, which is one of coupling or decoupling, equal to the second coupling state, which is one of coupling or decoupling? If the first coupling state and the second coupling state are the same, the method proceeds to step 1540. However, if the first coupling state and the second coupling state are different, the method proceeds to step 1550.

[0152] In step 1540, the output device 340 is controlled to output a coupling signal 345 indicating a first coupling state and a second coupling state (i.e., one of coupling or decoupling).

[0153] In step 1550, when the determined first coupling state differs from the second coupling state, the control output device 340 outputs a coupling signal 345 indicating the first coupling state (i.e., the attribute-based coupling state). That is, the arbitrator 570 is configured to assign a higher priority to the first coupling state than to the second coupling state. This is reflected in Table 1 below, as will be explained, through the rightmost efficiency column, such that the coupling state is determined by prioritizing, for example, HSM 510. The arbitrated coupling state independently follows the coupling state determined by DMM 560 only when no request is received from other modules.

[0154] Figure 15 The coupling states determined by DMM 560 according to some embodiments of the invention are illustrated. In some embodiments, DMM 560 is arranged to determine the coupling state of the second electric traction motor 212 based on a drive mode signal 440, which indicates the mode or gear selection of the powertrain, particularly its transmission, such as Drive (D), Neutral (N), and Reverse (R), i.e., the shifter position. As can be understood, DMM 560 is arranged not to request coupling state 1630 when the powertrain is not in Neutral, i.e., when D or R is selected or a gear of the transmission is selected. In such a state, DMM 560 may output a non-request NR signal. However, when N is selected, as indicated by drive mode signal 440, DMM 560 is arranged to output coupling signal 565 to request decoupling state 1640. Therefore, when N is selected, decoupling of the second electric traction motor 212 is requested.

[0155] As described above, some embodiments of the present invention include an arbitrator 570. The arbitrator 570 is arranged to receive one or more requests for the coupling state of the second electric traction motor 212, and to determine the overall or arbitrated coupling state of the second electric traction motor 212 and the second shaft 222. The arbitrator 570 is arranged to control the output device 340 of the controller 305 to output a coupling signal 345 indicating its coupling state. The arbitrator 570 is arranged to assign a predetermined priority or priority to at least some of the requests for coupling states from different modules. Table 1 below identifies the requests for coupling states received from the various modules of the controller 305, the default coupling state (i.e., no other requests), and the coupling state determined by the arbitrator 570.

[0156] Table 1

[0157]

[0158] C = Coupling, D = Decoupling, NR = No Request, X = Irrelevant.

[0159] Arbitrator 570 is configured to receive FDCSR signal 535 from FMM 530 at its input device. It is understood that arbitrator 570 also receives a plurality of additional coupling status request signals 515, 525, 565, i.e., additional coupling status request signals from each of modules 510, 520, 560. Each coupling status request signal indicates a request for the coupling status of the second electric traction motor 212 with at least one wheel of the second axle 222.

[0160] Reference Figure 10 , Figure 10 A method for determining the coupling state in the presence of an FDCSR 535 from an FMM 530 is illustrated. An arbitrator 570 is arranged to determine the arbitrated coupling state of the second electric traction motor 212 with at least one wheel of the second axle 222 based on the FDCSR signal 535 and at least one additional coupling state request signal 515, 525, 565. The arbitrator 570 is further arranged to determine the arbitrated coupling state of the second electric traction motor 212 if the priority of the FDCSR signal 535 exceeds that of the at least one additional coupling state request signal 515, 525, 565.

[0161] exist Figure 10 In step 1110, the arbitrator 570 is configured to receive an FDCSR signal 535 from the FMM 530. As described above, the FDCSR signal 535 indicates a coupling state request. For example, the FDCSR signal 535 indicates a request for one of the coupling or decoupling states as shown in Table 1.

[0162] In step 1120, arbitrator 570 is configured to receive any other coupling status request signals, i.e., any other coupling status request signals from modules 510, 520, 525, 525, 565, and 560. It should be understood that, as considered by Table 1, at some points in time, no other coupling status requests are received simultaneously with FDCSR 535.

[0163] In step 1130, the coupling state of the second electric traction motor 212 is determined based on FDCSR 535 and any other received coupling state requests. As can be understood from Table 1 above, when FDCSR signal 535 indicates a decoupling state (D), arbitrator 570 is arranged to determine the arbitrated coupling state as decoupling, regardless of the states of other coupling state request signals 515, 525, 565. Therefore, arbitrator 570 is arranged to determine the coupling state of motor 212 if the priority of FDCSR signal 535 exceeds that of any other coupling state request signal. In particular, arbitrator 570 is arranged to determine the decoupling state of the second electric traction motor 212 if the priority of FDCSR signal 535 indicating a request to decouple the second electric traction motor 212 exceeds that of any other coupling state request signal.

[0164] When the arbitrator 570 receives a high-speed coupling state request 515HSCSR signal from the HSM 510 indicating a request to disconnect the second electric traction motor 212 from the second shaft 222 (D), as can be understood from Table 1, when no FDCSR 535 (NR) is received, or when the FDCSR signal 535 indicates a coupling (C) request, the arbitrator 570 determines the arbitrated coupling state of the second electric traction motor 212 as decoupled based on the request from the HSM 510, in order to advantageously protect the second electric traction motor 212 from excessive rotational speed. Therefore, in case of conflict, the decoupling request from the HSM 510 has higher priority than the FDCSR 535.

[0165] In step 1140, the arbitrator 570 is arranged to output an arbitrated coupling request signal 575 indicating an arbitrated coupling state to control the coupling of the second electric traction motor 212 with at least one wheel (RL, RR) of the second axle 222. The arbitrated coupling request signal 575 is output via the output device 340 of the controller 305 to control the coupling of the second electric traction motor 212.

[0166] Figure 16The overall operation of system 300 is illustrated. Track 1701 represents an arbitrated coupling state request output as signal 345 by controller 305. Track 1702 represents the actual coupling state of the second electric traction motor 212 with at least one wheel (RL, RR) of the second axle 222. Track 1703 is a connection suppression signal, and track 1704 is a disconnection or decoupling state suppression signal.

[0167] As can be understood, during period 1710, DMM 560 determines the coupling state to be decoupled, for example, based on drive mode signal 440 indicating an efficiency-based drive mode. As indicated by 1703, the suppressed coupling state has no effect because the arbitrated coupling state is decoupled. During period 1720, DMM 560 determines the coupling state to be coupled based on the IDD drive mode indicated by drive mode signal 440. However, connection suppression signal 1703 indicates that the coupling state is suppressed, thus the actual coupling state is decoupled; that is, the coupling suppression state has higher priority than the coupling state requested by DMM 560. However, during period 1730, once the coupling state suppression signal 1703 indicates that the coupling state is not suppressed, the coupling state is realized. During period 1740, the coupling state is requested as the default coupling state for arbiter 570. However, as shown in trajectory 1704, the decoupling state is partially suppressed during period 1740, but this does not affect the coupling state during period 1740 because coupling is still requested by arbiter 570. However, during period 1750, when decoupling is requested by HSM 510, the coupling state remains because decoupling is still suppressed. Once the suppression is lifted during period 1760, the decoupling coupling state corresponding to the requested state of HSM 510 is requested by arbiter 570. During period 1760, LSM 520 requests the coupling state.

[0168] It should be understood that embodiments of the present invention can be implemented in hardware, software, or a combination of hardware and software. Any such software can be stored in the form of volatile or non-volatile storage devices (e.g., storage devices like ROM, whether erasable or rewritable) or in the form of memory (e.g., RAM, memory chips, devices, or integrated circuits), or stored on optically or magnetically readable media (e.g., CDs, DVDs, disks, or magnetic tapes). It will be understood that the storage devices and storage media are embodiments of machine-readable storage devices suitable for storing one or more programs that, when executed, implement embodiments of the present invention. Therefore, embodiments provide programs comprising code for implementing any of the systems or methods claimed in the preceding claims, and machine-readable storage devices for storing such programs. Furthermore, embodiments of the present invention can be electronically communicated via any medium, such as communication signals carried by wired or wireless connections, and embodiments appropriately include the foregoing.

[0169] All features disclosed in this specification (including any appended claims, abstract, and drawings) and / or all steps of any method or process so disclosed may be combined in any combination, except that at least some of such features and / or steps are mutually exclusive combinations.

[0170] Unless otherwise expressly stated, each feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by an alternative feature having the same, equivalent, or similar purpose. Therefore, unless otherwise expressly stated, each disclosed feature is merely one example of a general series of equivalent or similar features.

[0171] This invention is not limited to the details of any of the foregoing embodiments. The invention extends to any novel one or any novel combination of features disclosed in this specification (including any appended claims, abstract, and drawings), or to any novel one or any novel combination of steps of any method or process so disclosed. The claims should not be construed as covering only the foregoing embodiments, but also any embodiments falling within the scope of the claims.

Claims

1. A motor control system for a vehicle, the motor control system comprising one or more controllers, wherein, The vehicle includes an electric motor arranged to selectively couple to provide torque to at least one wheel of the vehicle's axle, and the control system includes: An input device for receiving a speed signal indicating the speed of the vehicle; A processing device is arranged to determine a deceleration rate of the vehicle based on the speed signal, and to determine a first low-speed threshold (910) based on the deceleration rate of the vehicle, and to determine a desired coupling state (525) of the motor and at least one wheel of the axle based on the speed signal, wherein the processing device is arranged to determine the desired coupling state as coupled based on a speed signal indicating that the vehicle speed is equal to or lower than the first low-speed threshold, and to determine the desired coupling state as not requested based on a speed signal indicating that the vehicle speed is higher than a second low-speed threshold (920), the unrequested coupling state indicating that a specific coupling state is not requested, wherein the second low-speed threshold represents a vehicle speed greater than the first low-speed threshold; and An output device is arranged to output a coupling signal when the desired coupling state is determined to be coupled, the coupling signal indicating a request to couple the motor to the at least one wheel of the axle.

2. The control system according to claim 1, wherein, The processing device is arranged to determine the desired coupling state based on a speed signal indicating that the vehicle speed is between a first low-speed threshold and a second low-speed threshold, according to the threshold that most recently intersects between the first low-speed threshold and the second low-speed threshold.

3. The control system according to claim 2, wherein, The processing device is arranged such that: When the most recently intersected threshold is the first low-speed threshold, the desired coupling state is determined to be coupled; and When the threshold of the most recent intersection is the second low-speed threshold, the desired coupling state is determined to be no request.

4. The control system according to claim 1, 2 or 3, wherein: The input device is arranged to receive a signal indicating the coupling state (470) of the motor with the at least one wheel of the axle; The processing device is configured to control the output device to output a coupling suppression signal (535) based on a speed signal indicating that the vehicle speed is equal to or lower than a third low speed threshold (930) and a coupling state signal indicating that the motor is decoupled from the at least one wheel of the axle.

5. The control system according to claim 4, wherein, The processing device is configured to control the output device to stop the output of the coupling suppression signal based on a speed signal indicating that the vehicle speed is equal to or higher than a fourth low-speed threshold.

6. The control system according to claim 1, 2 or 3, wherein, The processing device is arranged to increase the first low-speed threshold according to the deceleration rate being equal to or greater than a predetermined deceleration rate.

7. A powertrain comprising a control system according to any one of claims 1 to 6.

8. A vehicle comprising a control system according to any one of claims 1 to 6 or comprising a powertrain according to claim 7.

9. A method for controlling the coupling of an electric motor to provide torque to at least one wheel of a vehicle axle, the method comprising: Receive a speed signal indicating the speed of the vehicle; The deceleration rate of the vehicle is determined based on the speed signal; A first low-speed threshold is determined based on the vehicle's deceleration rate; as well as The desired coupling state between the motor and at least one wheel on the axle is determined based on the speed signal, wherein, The desired coupling state is determined to be coupled based on a speed signal indicating that the vehicle speed is equal to or lower than the first low-speed threshold; and The desired coupling state is determined as not requested based on a speed signal indicating that the vehicle speed is higher than a second low speed threshold. The not requested coupling state indicates that a specific coupling state is not requested, wherein the second low speed threshold represents a vehicle speed greater than the first low speed threshold.

10. The method of claim 9, further comprising outputting a coupling signal when the desired coupling state is determined to be coupled, the coupling signal indicating a request to couple the motor to the at least one wheel of the axle.

11. The method according to claim 9 or 10, wherein, The desired coupling state is determined based on the speed signal indicating that the vehicle speed is between the first low speed threshold and the second low speed threshold, according to the threshold that most recently intersects between the first low speed threshold and the second low speed threshold.

12. The method according to claim 11, wherein, The method includes: When the threshold of the most recent intersection is equal to the first low-speed threshold, the desired coupling state is determined to be coupled; and When the threshold of the most recent intersection is the second low-speed threshold, the desired coupling state is determined to be no request.

13. The method according to claim 9 or 10, comprising: Receive a signal indicating the coupling state of the motor and at least one wheel of the axle; A coupling suppression signal is output based on a speed signal indicating that the vehicle speed is equal to or lower than a third low-speed threshold and a coupling state signal indicating that the motor is decoupled from at least one wheel of the axle.

14. The method of claim 13, further comprising stopping the output of the coupling suppression signal based on a speed signal indicating that the vehicle speed is equal to or higher than a fourth low speed threshold.

15. The method according to claim 9 or 10, wherein, The first low-speed threshold is increased based on whether the deceleration rate is equal to or greater than the predetermined deceleration rate.

16. A computer software configured to perform the method according to any one of claims 9 to 15 when executed by a computer.

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