Electromechanical control device and method

Abstract

An embodiment of the present invention provides an electro-machine control system for a vehicle, the electro-machine control system including one or more controllers, the vehicle including an electric machine configured to be selectively coupleable to provide torque to at least one wheel of an axle of the vehicle, the control system having input means for receiving a speed signal indicative of a speed of the vehicle, processing means configured to determine a coupling status of the electric machine to the at least one wheel of the axle in dependence on the speed signal, and output means configured to output a coupling signal indicative of the coupling status to control coupling of the electric machine to the at least one wheel of the axle.

Description

Technical Field

[0001] The present disclosure relates to the control of an electromechanical machine, and in particular, the present invention relates to (but is not limited to) controlling the coupling of an electromechanical machine. Aspects of the present invention relate to control systems, power trains, vehicles, methods, and computer software.

Background Art

[0002] Vehicles powered by multiple power sources or traction power sources, such as internal combustion engines and one or more electromechanical machines or motors, are becoming increasingly well-known. However, the management of multiple traction power sources can be problematic. An object of embodiments of the present invention is to at least mitigate one or more of the problems of the prior art.

Summary of the Invention

[0003] Aspects and embodiments of the present invention provide a control system, a power train, a vehicle, a method, and a computer software as set forth in the appended claims.

[0004] According to one aspect of the present invention, an electromechanical control system for a vehicle is provided. The electromechanical control system includes one or more controllers, and the vehicle includes an electromechanical machine configured to be selectively coupled to apply torque to at least one wheel of an axle by processing means configured to determine the coupling state of the electromechanical machine to the at least one wheel of the axle. Advantageously, the processing means is configured to determine the coupling of the electromechanical machine to at least one wheel of the axle.

[0005] According to another aspect of the present invention, an electromechanical control system for a vehicle is provided. The electromechanical control system includes one or more controllers. The vehicle includes an electromechanical device configured to be selectively coupled to provide torque to at least one wheel of an axle of the vehicle. The electromechanical control system includes one or more controllers and an electromechanical device configured to be selectively coupled to provide torque to at least one wheel of an axle of the vehicle. The control system includes input means for receiving a speed signal indicative of the speed of the vehicle, processing means configured to determine the coupling state of the electromechanical device to at least one wheel of the axle depending on the speed signal, and output means configured to output a coupling signal indicative of the coupling state for controlling the coupling of the electromechanical device to at least one wheel of the axle. Advantageously, the processing means is configured to determine the coupling of the electromechanical device to at least one wheel of the axle depending on the speed of the vehicle.

[0006] Optionally, the processing means is configured to determine the desired coupling state as uncoupled depending on the vehicle speed being equal to or greater than a first high speed threshold. Advantageously, the uncoupled state prevents excessive rotational speed of the electromechanical device.

[0007] The processing means may optionally determine the desired coupling state as unrequested depending on the vehicle speed indicated by the speed signal being below a second high speed threshold. Advantageously, the processing means does not require a coupling state at low rotational speeds of the electromechanical device. Advantageously, two thresholds are used, thereby improving the control of the coupling. The second high speed threshold may represent a lower vehicle speed than the first high speed threshold. Advantageously, unrequested is determined at a speed lower than the uncoupled state.

[0008] Optionally, the output means is configured to output a coupling signal indicative of a request to uncouple the electromechanical device from at least one wheel of the axle depending on the desired coupling state being the uncoupled state. Advantageously, the output means indicates the desired decoupling depending on the determined decoupled state.

[0009] Optionally, the processing means is configured to determine a desired engagement state depending on the speed signal indicating a vehicle speed between a first and a second high threshold value depending on the last crossing of the first and second high threshold values. Advantageously, excessive or frequent switching of the engagement state is prevented.

[0010] The input means may be configured to receive a temperature signal, and the processing means is configured to determine an engagement state in response to the temperature signal. Advantageously, the temperature is taken into account when determining the engagement state.

[0011] The processing means may be configured to determine one or both of the first and second high threshold values depending on the temperature signal. Advantageously, one or both of the threshold values may respond to the temperature.

[0012] Optionally, the processing means is configured to reduce one or both of the first and second high threshold values depending on the temperature signal indicating at least a first predetermined temperature. Advantageously, decoupling may be determined at a lower speed in the presence of a higher temperature. The first predetermined temperature may be at least 35°C. Advantageously, if the temperature is at least 35°C, one or both of the threshold values may be reduced.

[0013] Optionally, the processing means is configured to reduce one or both of the first and second high threshold values depending on the temperature signal indicating below a second predetermined temperature. Advantageously, decoupling may be determined at a lower speed in the presence of a lower temperature.

[0014] Optionally, the processing means is configured to decrease one or both of the first and second high threshold values in proportion to the temperature. Advantageously, decoupling may be determined at a lower speed in proportion to the temperature. Optionally, one or both of the first and second high threshold values are reduced in proportion to the temperature in the range between -10°C and -20°C. Advantageously, in the range between -10°C and -20°C, decoupling may be determined in proportion to the temperature.

[0015] The second predetermined temperature may be -5 °C or lower. Advantageously, the disconnection may be determined at a low speed in the presence of a temperature of -5 °C or lower. Optionally, the disconnection may be determined at an even lower speed if a temperature of -10 °C or lower is present.

[0016] The input means may be configured to receive a charging signal indicating the state of charge (SoC) of one or more batteries for supplying power to the electromechanical machine. The one or more batteries may be traction batteries. The processing means is optionally configured to determine the engagement state depending on the charging signal. Advantageously, the state of charge of the one or more batteries may be taken into account when determining the engagement.

[0017] The processing means may be configured to determine a second high-speed threshold depending on the charging signal. Advantageously, the determination of the no-demand state may be made depending on the state of charge.

[0018] If the controller according to claim 10 is subordinate through claim 2, the processing means is configured to determine the desired engagement state of the electromechanical machine as a disconnection depending on the charging signal indicating that the state of charge of one or more batteries is below a predetermined threshold and the speed signal indicating a vehicle speed below a second threshold.

[0019] The input means may be configured to receive one or more further signals indicating the state of one or more further vehicle subsystems or one or more further attributes of the vehicle. The processing means may be configured to determine the desired engagement state of the electromechanical machine at least partially depending on the one or more further signals. Advantageously, the state of one or more further vehicle subsystems or one or more further attributes may be taken into account when determining the engagement state.

[0020] The processing means is optionally configured to determine the desired engagement state of the electromechanical machine with priority given to the speed signal over the one or more further signals. Advantageously, the speed signal is given a higher priority.

[0021] The first high-speed threshold can represent a vehicle speed less than the desired decoupling vehicle speed such that when the vehicle is accelerating, the electromechanical device is decoupled from at least one wheel of the axle when the vehicle reaches the desired decoupling vehicle speed. Advantageously, a delay in performing the disconnection may be accounted for in order to prevent an excessive rotational speed of the electromechanical device.

[0022] According to yet another aspect of the present invention, a powertrain is provided that includes a system as described above.

[0023] According to yet another aspect of the present invention, a vehicle is provided that is configured to include the control system or powertrain as described above.

[0024] The electromechanical device may be configured to be selectively coupled to provide torque to at least one wheel of a first axle of the vehicle, and the vehicle optionally includes a second power source configured to provide torque to at least one wheel of a second axle of the vehicle. Advantageously, the coupling of the electromechanical device is determined by the torque optionally provided to the second axle by a second electromechanical device. The second power source may be constituted by a second electromechanical device. Advantageously, the vehicle may be an electric vehicle.

[0025] According to another aspect of the present invention, a method is provided for controlling the coupling of an electromechanical device to provide torque to at least one wheel of an axle of a vehicle, the method comprising receiving a speed signal indicative of the speed of the vehicle, determining a coupling state of the electromechanical device to at least one wheel of the axle depending on the speed signal, and outputting a coupling signal indicative of the coupling state to control the coupling of the electromechanical device to at least one wheel of the axle.

[0026] Determining the coupling state may include determining a desired coupling state of the electromechanical device to at least one wheel of the axle depending on the speed signal. The desired coupling state may be determined to be uncoupled depending on the speed signal indicating a vehicle speed equal to or higher than a first high-speed threshold.

[0027] The desired coupling state may be determined as a no - request depending on the speed signal indicating a vehicle speed below a second high - speed threshold, where the second high - speed threshold represents a lower vehicle speed than the first high - speed threshold.

[0028] This method may include outputting a coupling signal indicating a request to decouple the electromechanics from at least one wheel of the axle depending on the desired coupling state being uncoupled.

[0029] This method may include determining the desired coupling state depending on the speed signal indicating a vehicle speed between the first and second high - speed thresholds depending on the last crossing of the first and second high - speed thresholds.

[0030] This method may include receiving a temperature signal. Optionally, the coupling state is determined depending on the temperature signal.

[0031] This method may include receiving a charge signal indicating the state of charge of one or more batteries for powering the electromechanics and determining the coupling state depending on the charge signal.

[0032] The processing means may be configured to determine the desired coupling state as coupled depending on a speed signal indicating a vehicle speed equal to or below a first low - speed threshold. Advantageously, the processing means is configured to determine the coupling of the electromechanics as being coupled to at least one wheel of the axle at low speed.

[0033] According to one aspect of the present invention, an electromechanical control system for a vehicle is provided. The electromechanical control system includes one or more controllers. The vehicle includes an electromechanical device configured to be selectively coupled to at least one wheel of an axle of the vehicle to provide torque to the at least one wheel. The control system includes input means for receiving a speed signal indicative of the speed of the vehicle, and processing means configured to determine a desired coupling state of the electromechanical device to at least one wheel of the axle depending on the speed signal. A vehicle electromechanical control system is provided, characterized in that the processing means determines the desired coupling state as coupled depending on the speed signal indicating a vehicle speed equal to or below a first low speed threshold, and determines the desired coupling state as no requirement depending on the speed signal indicating a vehicle speed exceeding a second low speed threshold, where the second low speed threshold indicates a vehicle speed greater than the first low speed threshold. The output means is assigned to output a coupling signal indicating a request to couple the electromechanical device to at least one wheel of the axle depending on the desired coupling state being coupled. Advantageously, the processing means does not require a coupling state at a higher rotational speed of the electromechanical device. Advantageously, two thresholds are used, thereby improving the control of the coupling. Advantageously, no requirement is determined at a rotational speed higher than the uncoupled state.

[0034] The processing means may be configured to determine the desired coupling state depending on the speed signal indicating a vehicle speed between a first low speed threshold and a second low speed threshold, and may determine the desired coupling state depending on a threshold that last intersects the first and second low speed thresholds. Advantageously, excessive or frequent switching of the coupling state is prevented.

[0035] The processing means is optionally configured to determine the desired coupling state as coupled if the last intersecting threshold is the first low speed threshold. Advantageously, the coupling state is maintained if it was more recently selected.

[0036] The processing means is optionally configured to determine that the desired coupling state is without requirement when the last crossed threshold value is the second low speed threshold value. Advantageously, the state without requirement is maintained when it was more recently selected.

[0037] The input means may be configured to receive a signal indicating the electromechanical coupling state for at least one wheel of an axle. Advantageously, the actual coupling state is indicated to the processing means.

[0038] The processing means may be configured to control the output means to output a coupling prohibition signal depending on the vehicle speed being equal to or below a third low speed threshold value and the coupling state signal indicating that the electromechanical is disengaged from at least one wheel of the axle. Advantageously, coupling is prohibited when the electromechanical is disengaged at a very low speed.

[0039] The processing means is optionally configured to control the output means to stop outputting the coupling prohibition signal depending on the vehicle speed signal indicating a vehicle speed above a fourth low speed threshold value. Advantageously, the inhibition is released when the vehicle speed increases.

[0040] The processing means may be configured to determine the deceleration rate of the vehicle depending on the speed signal and to determine a first low speed threshold value depending on the deceleration rate of the vehicle. Advantageously, the first low speed threshold value is adapted to the deceleration rate.

[0041] The processing means may be configured to increase the first low speed threshold value depending on the deceleration rate being above a predetermined deceleration rate. Advantageously, when the vehicle is decelerating more rapidly, more time is provided to achieve coupling.

[0042] According to one aspect of the invention, a powertrain including a system as described above is provided.

[0043] According to one aspect of the invention, a vehicle comprising a control system or a powertrain as described above is provided.

[0044] According to one aspect of the present invention, a method for controlling an electromechanical coupling to apply torque to at least one wheel of an axle of a vehicle is provided, the method comprising receiving a speed signal indicative of the speed of the vehicle and determining a desired coupling state of the electromechanical coupling to at least one wheel of the axle depending on the speed signal. The desired coupling state is determined as coupled depending on the speed signal indicating a vehicle speed below a first low speed threshold, and determined as no requirement depending on the speed signal indicating a vehicle speed above a second low speed threshold, the second low speed threshold indicating a higher vehicle speed than the first low speed threshold.

[0045] The method includes outputting a coupling signal indicative of a requirement to couple the electromechanical coupling to at least one wheel of the axle depending on the desired coupling state being coupled.

[0046] The desired coupling state is optionally determined depending on the speed signal indicating a vehicle speed between the first and second low speed thresholds depending on the threshold at which the speed signal last crosses the first and second low speed thresholds.

[0047] The method may include determining that the desired coupling state is coupled when the last crossed threshold is the first low speed threshold. The method may include determining that the desired coupling state is no requirement when the last crossed threshold is the second low speed threshold.

[0048] The method optionally includes receiving a signal indicative of the coupling state of the electromechanical coupling to at least one wheel of the axle.

[0049] The method optionally includes outputting a coupling inhibition signal depending on the speed signal indicating a vehicle speed equal to or below a third low speed threshold. The coupling state signal may indicate that the electromechanical coupling is disengaged from at least one wheel of the axle.

[0050] The method may include stopping the output of the engagement inhibition signal depending on the speed signal indicating a vehicle speed equal to or higher than a fourth low speed threshold.

[0051] Optionally, the method includes determining a deceleration rate of the vehicle depending on the speed signal. The method may include determining a first low speed threshold depending on the deceleration rate of the vehicle.

[0052] The processing means may be configured to increase the first low speed threshold depending on the deceleration rate being equal to or higher than a predetermined deceleration rate.

[0053] According to one aspect of the invention, an electromechanical control system for a vehicle is provided, the electromechanical control system comprising one or more controllers, the vehicle comprising an electromechanical machine configured to be selectively connectable to provide torque to at least one wheel of an axle of the vehicle, the control system having input means for receiving a speed signal indicative of the speed of the vehicle, and processing means configured to determine a desired engagement state of the electromechanical machine to at least one wheel of the axle depending on the speed signal. The processing means determines the desired engagement state as engaged depending on the speed signal indicating a vehicle speed equal to or lower than a first low speed threshold, and determines the desired engagement state as no requirement depending on the speed signal indicating a vehicle speed exceeding a second low speed threshold, the second low speed threshold indicating a vehicle speed higher than the first low speed threshold, and output means assigned to output a coupling signal indicating a request to couple the electromechanical machine to at least one wheel of the axle depending on the desired engagement state being engaged. Advantageously, the processing means does not require an engagement state at a higher rotational speed of the electromechanical machine. Advantageously, two thresholds are used, thereby improving the control of the engagement. Advantageously, no requirement is determined at a rotational speed higher than the disengaged state.

[0054] The processing means may be configured to determine a desired engagement state depending on the speed signal indicating a vehicle speed between a first low speed threshold and a second low speed threshold, and may determine the desired engagement state depending on the threshold that last crosses the first and second low speed thresholds. Advantageously, excessive or frequent switching of the engagement state is prevented.

[0055] Optionally, the processing means is configured to determine the desired engagement state as engaged when the last crossed threshold is the first low speed threshold. Advantageously, the engaged state is maintained if it was selected more recently.

[0056] Optionally, the processing means is configured to determine the desired engagement state as no requirement when the last crossed threshold is the second low speed threshold. Advantageously, the no requirement state is maintained if it was selected more recently.

[0057] The input means may be configured to receive a signal indicating the electromechanical engagement state of at least one wheel of an axle. Advantageously, the actual engagement state is indicated to the processing means.

[0058] The processing means is configured to control the output means to output a coupling prohibition signal depending on the speed signal indicating a vehicle speed equal to or less than a third low speed threshold and the coupling state signal indicating that the electromechanical is disengaged from at least one wheel of the axle. Advantageously, coupling is prohibited if the electromechanical is disengaged at a very low speed.

[0059] Optionally, the processing means is configured to control the output means to stop outputting the coupling prohibition signal depending on the speed signal indicating a vehicle speed equal to or higher than a fourth low speed threshold. Advantageously, the inhibition is released when the vehicle speed increases.

[0060] The processing means may be configured to determine a deceleration rate of the vehicle depending on the speed signal and determine a first low speed threshold depending on the deceleration rate of the vehicle. Advantageously, the first low speed threshold is adaptable to the deceleration rate.

[0061] The processing means may be configured to increase the first low speed threshold value depending on the deceleration rate being equal to or higher than a predetermined deceleration rate. Advantageously, when the vehicle is decelerating more rapidly, more time is provided to achieve the engagement.

[0062] According to one aspect of the present invention, a powertrain including the above-described system is provided.

[0063] According to one aspect of the present invention, a vehicle including the above-described control system or powertrain is provided.

[0064] According to one aspect of the present invention, a method for controlling an electromechanical engagement to apply torque to at least one wheel of an axle of a vehicle is provided, the method comprising receiving a speed signal indicative of a speed of the vehicle and determining a desired engagement state of the electromechanical for at least one wheel of the axle depending on the speed signal. The desired engagement state is determined as an engagement depending on the speed signal indicating a vehicle speed equal to or lower than a first low speed threshold value, and is determined as a no requirement depending on the speed signal indicating a vehicle speed equal to or higher than a second low speed threshold value, the second low speed threshold value indicating a vehicle speed higher than the first low speed threshold value.

[0065] The method includes outputting an engagement signal indicative of a request to engage the electromechanical to at least one wheel of the axle depending on the desired engagement state being an engagement.

[0066] The desired engagement state is optionally determined depending on the speed signal indicating a vehicle speed between the first and second low speed threshold values depending on the threshold value at which the speed signal last crosses the first and second low speed threshold values. The method may include determining that the desired engagement state is an engagement when the last crossed threshold value is the first low speed threshold value. The method may include determining that the desired engagement state is a no requirement when the last crossed threshold value is the second low speed threshold value.

[0067] The method optionally includes receiving a signal indicative of an electromechanical coupling state for at least one wheel of an axle.

[0068] The method optionally includes outputting a coupling inhibition signal depending on the vehicle speed being equal to or below a third low speed threshold. The coupling state signal may indicate that the electromechanical is disengaged from at least one wheel of the axle.

[0069] The method may optionally include stopping the output of the coupling inhibition signal depending on the vehicle speed being above a fourth low speed threshold.

[0070] Optionally, the method includes determining a deceleration rate of the vehicle depending on the speed signal. The method may include determining a first low speed threshold depending on the deceleration rate of the vehicle.

[0071] The processing means may be configured to increase the first low speed threshold depending on the deceleration rate being equal to or above a predetermined deceleration rate.

[0072] According to another aspect of the invention, there is provided computer software configured to perform a method as described above when executed by a computer. The computer software may be stored on a computer-readable medium. The computer software may be stored in contact with a computer-readable medium.

[0073] According to one aspect of the present invention, an electromechanical control system for a vehicle is provided. The electromechanical control system includes one or more controllers. The vehicle includes an electromechanical device configured to be selectively coupled to provide torque to at least one wheel of an axle of the vehicle. The control system includes input means for receiving a failure-derived coupling state request signal indicating a request for the coupling state of the electromechanical device with respect to at least one wheel of the axle, processing means configured to determine the coupling state of the electromechanical device with respect to at least one wheel of the axle depending on the failure-derived coupling state request signal, and output means configured to output a coupling signal indicating the determined coupling state for controlling the coupling of the electromechanical device to at least one wheel of the axle. Advantageously, the coupling state is determined depending on the failure-derived coupling state request.

[0074] According to one aspect of the present invention, an electromechanical control system for a vehicle is provided. The electromechanical control system includes one or more control devices. The vehicle includes an electromechanical device configured to be selectively coupled to provide torque to at least one wheel of an axle of the vehicle. The control device includes input means for receiving a coupling state request signal derived from a failure and at least one further coupling state request signal, each coupling state request signal indicating a request for the coupling state of the electromechanical device with respect to at least one wheel of the axle; processing means configured to determine the coupling state of the electromechanical device with respect to at least one wheel of the axle depending on the coupling state request signal derived from the failure and the at least one further coupling state request signal, the processing means being configured to determine the coupling state of the electromechanical device giving priority to the coupling state request signal derived from the failure over the at least one further coupling state request signal; and output means configured to output a coupling signal indicating the determined coupling state and control the coupling of the electromechanical device to at least one wheel of the axle of the vehicle, the output means performing the control of the coupling state. Advantageously, the coupling state is determined depending on the failure-derived coupling state request.

[0075] The input means may be configured to receive a high-speed coupling state request signal indicating a request to disconnect the electromechanical device from at least one wheel of the axle. The processing means may be configured to determine the coupling state of the electromechanical device with respect to at least one wheel of the axle depending on the high-speed coupling state request signal, with priority over the fault-derived coupling state request signal. The output means may be configured to output a coupling signal indicating the determined coupling state. Advantageously, the high-speed coupling state request is prioritized.

[0076] The fault-derived coupling state request signal optionally indicates a request to couple the electromechanical device to at least one wheel of the vehicle's axle, and the processing means is configured to determine the coupling state such that at least one additional coupling state request signal indicating a request to disconnect the electromechanical device from at least one wheel of the vehicle's axle is coupled with priority. The output means may be configured to output a coupling signal indicating the determined coupling state. Advantageously, priority is given to the coupling state for coupling the electromechanical device.

[0077] The fault-derived coupling state request signal may indicate a request to disconnect the electromechanical device from at least one wheel of the vehicle's axle, and the processing means is configured to determine that the coupling state is disconnected with priority over at least one additional coupling state request signal indicating a request to couple at least one wheel of the vehicle's axle, and the output means may be configured to output a coupling signal indicating the determined coupling state. Advantageously, priority is given to the coupling state for disconnecting the electromechanical device.

[0078] The input means may be configured to receive a speed signal indicating the speed of the vehicle, and the processing means may be configured to delay controlling the output means to output a coupling state signal indicating a change in the coupling state depending on the speed signal indicating at least a predetermined speed when it is determined to change the coupling state from uncoupled to coupled depending on the fault-derived coupling state request signal. Advantageously, the change in the coupling state is delayed depending on the speed of the vehicle.

[0079] The defined speed may be a speed greater than substantially 0 km / h. Advantageously, the change of the coupling state is postponed until the vehicle moves.

[0080] At least one further coupling state request signal may be determined depending on a speed signal indicating the speed of the vehicle. Advantageously, the further coupling state request signal is determined depending on the speed of the vehicle.

[0081] At least one further coupling state request signal may be determined depending on a driving mode signal indicating the driving mode of the vehicle. Advantageously, the further coupling state request signal is determined depending on the driving mode.

[0082] According to one aspect of the present invention, a powertrain including any of the above-described systems is provided.

[0083] According to one aspect of the present invention, a vehicle including the control system as described above or the powertrain as described above is provided.

[0084] The electric machine may be configured to be selectively coupled to provide torque to at least one wheel of a first axle of the vehicle, and the vehicle includes a second power source configured to provide torque to at least one wheel of a second axle of the vehicle. The second power source may be composed of a second electric machine.

[0085] According to one aspect of the present invention, there is provided a method for controlling an electromechanical coupling to supply torque to at least one wheel of an axle of a vehicle, the method comprising receiving a fault-derived coupling state request, a fault-derived coupling state request, a signal, and at least one further coupling state request signal, each coupling state signal indicating a request for an electromechanical coupling state for at least one wheel of the axle; determining an electromechanical coupling state for at least one wheel of the axle depending on the fault-derived coupling state request signal and the at least one further coupling state request signal, with the fault-derived coupling state request signal taking precedence over the at least one further coupling state request signal; and outputting a coupling signal indicating the determined coupling state to control the coupling between the electromechanical machine and at least one wheel of the axle.

[0086] The method may include receiving a high-speed coupling state request signal indicating a request to disconnect the electromechanical machine from at least one wheel of the axle, determining the coupling state of the electromechanical machine to at least one wheel of the axle depending on the high-speed coupling state request signal taking precedence over the fault-derived coupling state request signal, and outputting a coupling signal indicating the determined coupling state.

[0087] The fault-derived coupling state request signal may indicate a request to couple the electromechanical machine to at least one wheel of the axle of the vehicle. The method may include determining the coupling state as a coupling, with priority given to the case where at least one further coupling state request signal indicates a request to disconnect at least one wheel of the axle of the vehicle. The method may include outputting a coupling signal indicating the determined coupling state.

[0088] The coupling state request signal resulting from a fault may indicate a request to disconnect the electromechanical machine from at least one wheel of the axle of the vehicle. The method may include determining the coupling state as a non-coupling, with priority given to the case where at least one further coupling state request signal indicates a request to couple at least one wheel of the axle of the vehicle. The method may include outputting a coupling signal indicating the determined coupling state.

[0089] The method may include receiving a speed signal indicative of the speed of a vehicle and determining a change in the coupling state from uncoupled to coupled in response to a coupling state request signal resulting from a fault. The method can include delaying the output of a coupling state signal indicative of the change in the coupling state depending on the speed signal indicating at least a predetermined speed.

[0090] The predetermined speed may be a speed greater than substantially 0 km / h.

[0091] The method may include determining at least one further coupling state request signal depending on a speed signal indicative of the speed of the vehicle.

[0092] The method may include determining at least one further coupling state request signal depending on an operation mode signal indicative of the operation mode of the vehicle.

[0093] According to another aspect of the present invention, there is provided computer software configured to execute a method as described above when executed by a computer. The computer software may be stored on a computer-readable medium. The computer software may be stored in contact with the computer-readable medium.

[0094] According to one aspect of the present invention, an electromechanical control system for a vehicle is provided, the electromechanical control system including one or more controllers, the vehicle comprising an electromechanical machine arranged to be selectively coupled to provide torque to at least one wheel of an axle of the vehicle, the control system comprising input means arranged to receive a status signal indicative of the state of coupling of the electromechanical machine to at least one wheel of an axle of the vehicle; output means arranged to output a coupling signal for controlling the coupling of the electromechanical machine to at least one wheel of the axle; and processing means arranged to determine the coupling state of the electromechanical machine to at least one wheel of the axle and to control the output means to output a coupling signal indicative of the determined coupling state, the processing means being configured to control the output means to output a coupling signal indicative of a retry of a change in the coupling state depending on the speed signal.

[0095] Advantageously, a change in the coupling state is retried.

[0096] According to one aspect of the present invention, an electromechanical control system for a vehicle is provided. The electromechanical control system includes one or more controllers, the vehicle comprising an electromechanical machine arranged to be selectively coupled to provide torque to at least one wheel of an axle of the vehicle, the control system comprising input means arranged to receive a speed signal indicative of the speed of the vehicle and a status signal indicative of the state of coupling of the electromechanical machine to at least one wheel of an axle of the vehicle; output means arranged to output a coupling signal for controlling the coupling of the electromechanical machine to at least one wheel of the axle; and processing means arranged to determine the coupling state of the electromechanical machine to at least one wheel of the axle and to control the output means to output a coupling signal indicative of the determined coupling state, the processing means being configured to control the output means to output a coupling signal indicative of a retry of a change in the coupling state depending on the speed signal depending on the status signal indicating that a change in the coupling state of the electromechanical machine to at least one wheel of the axle has failed depending on the determined coupling state. Advantageously, a change in the coupling state is retried depending on the status signal.

[0097] The processing means may be configured to delay controlling the output means to output a coupling signal indicating a retry of the change of the coupling state depending on the speed signal indicating that the speed of the vehicle is at least a predetermined minimum speed. Advantageously, the change of the coupling state is retried depending on the speed of the vehicle.

[0098] The predetermined speed is optionally a speed greater than substantially 0 km / h. Advantageously, the change of the coupling state is retried when the vehicle is moving. In some embodiments, the change of the coupling state is retried only when the vehicle is moving.

[0099] Optionally, the processing means is configured to delay controlling the output means to output a coupling signal indicating a retry of the change of the coupling state depending on the speed signal indicating that the speed of the vehicle is below a predetermined maximum speed. Advantageously, the change of the coupling state is retried up to a predetermined maximum speed. The maximum speed may be less than 50 km / h. The maximum speed may be less than 20 km / h.

[0100] The processing means is optionally configured to control the output means to output a coupling signal indicating a retry of the change of the coupling state depending on the speed signal up to a predetermined maximum number of times. Advantageously, the change of the coupling state is retried up to a predetermined maximum number of times. The predetermined maximum number of times may be 5 times.

[0101] According to one aspect of the present invention, a powertrain including the above-described system is provided.

[0102] According to one aspect of the present invention, a vehicle including the above-described control system or the above-described powertrain is provided.

[0103] The electric machine may be configured to be selectively coupled to provide torque to at least one wheel of a first axle of a vehicle, and the vehicle includes a second source of power configured to provide torque to at least one wheel of a second axle of the vehicle. The second power source may be composed of a second electric machine.

[0104] According to one aspect of the present invention, a method for controlling the coupling of an electric machine to supply torque to at least one wheel of an axle of a vehicle is provided. The method includes receiving a speed signal indicating the speed of the vehicle and a state signal indicating the state of the coupling of the electric machine to at least one wheel of the axle of the vehicle, determining the state of the coupling of the electric machine to at least one wheel of the axle of the vehicle, determining the coupling state of the electric machine to at least one wheel of the axle and outputting a coupling signal indicating the determined coupling state to control the coupling of the electric machine to at least one wheel of the axle, determining, depending on a change in the determined coupling state in response to the state signal, a failure to change the coupling state of the electric machine to at least one wheel of the axle, and outputting, depending on the determined failure, a coupling signal indicating a retry of the change in the coupling state depending on the speed signal.

[0105] This method may include delaying the output of a coupling signal indicating a retry of the change in the coupling state depending on the speed signal indicating that the speed of the vehicle is at least a predetermined minimum speed.

[0106] The predetermined speed may be a speed greater than substantially 0 km / h.

[0107] This method may include delaying the output of a coupling signal indicating a retry of the change in the coupling state depending on the speed signal indicating that the speed of the vehicle is below a predetermined maximum speed.

[0108] The maximum speed may be less than 50 km / h. The maximum speed may be less than 20 km / h.

[0109] The method may include outputting a coupling signal indicating a retry of a change in the coupled state depending on a speed signal up to a predetermined maximum number of times. The predetermined maximum number of times may be 5 times.

[0110] According to one aspect of the present invention, an electromechanical control system for a vehicle is provided, the electromechanical control system including one or more controllers, the vehicle comprising an electromechanical machine selectively and operably arranged to provide torque to at least one wheel of an axle of the vehicle, the control system comprising input means for receiving at least one attribute signal indicative of one or more attributes of the vehicle; output means arranged to output a coupling signal for controlling the coupling of the electromechanical machine to at least one wheel of the axle; and processing means arranged to determine the coupling state of the electromechanical machine to the at least one wheel of the axle depending on the at least one attribute signal, the processing means being arranged to control the output means to output a coupling signal indicative of the determined coupling state at a frequency lower than a predetermined frequency indicative of a change in the coupling state, the predetermined frequency being determined depending on a predetermined period from the last change in the coupling state. Advantageously, an overly frequent change in the coupling state is prevented.

[0111] According to one aspect of the present invention, an electromechanical control system for a vehicle is provided. The electromechanical control system includes one or more controllers, and the vehicle is provided with an electromechanical device that is selectively coupled to at least one wheel of the vehicle axle to provide torque to the at least one wheel. The control system includes input means for receiving at least one attribute signal indicating one or more attributes of the vehicle; output means arranged to output a coupling signal for controlling the coupling of the electromechanical device to at least one wheel of the vehicle axle; and processing means arranged to determine the coupling state of the electromechanical device to the at least one wheel of the vehicle axle depending on the at least one attribute signal, the processing means being arranged to control the output means to output a coupling signal indicating the determined coupling state, and the processing means is arranged to defer controlling the output means to output a coupling signal indicating a change in the coupling state until a predetermined period has elapsed since the last change in the coupling state indicated by the coupling signal. Advantageously, excessive frequent changes in the coupling state are prevented.

[0112] The predetermined period may be 30 seconds. Advantageously, frequent changes in the coupling state are prevented.

[0113] The predetermined period may be 10 seconds. The predetermined period may be 5 seconds. Advantageously, regular changes in the coupling state are prevented.

[0114] The change in the coupling state may be from a coupled state to an uncoupled state. The change in the coupling state may be from uncoupled to coupled. Advantageously, changes in the coupling state from decoupling to coupling or from coupling to decoupling are prevented.

[0115] The at least one attribute signal may be composed of a speed signal indicating the speed of the vehicle. Advantageously, the coupling state may be determined depending on the speed of the vehicle.

[0116] At least one attribute signal may be composed of a driving mode signal indicating the driving mode of the vehicle. Advantageously, the coupling state may be determined depending on the driving mode of the vehicle.

[0117] According to one aspect of the present invention, a powertrain comprising a system as described above is provided. According to one aspect of the present invention, a vehicle comprising a control system as described above or a powertrain as described above is provided.

[0118] The electric machine may be configured to be selectively coupled to provide torque to at least one wheel of a first axle of the vehicle. The vehicle comprises a second power source configured to provide torque to at least one wheel of a second axle of the vehicle. The second power source may be composed of a second electric machine.

[0119] According to one aspect of the present invention, a method for controlling the coupling of an electric machine to supply torque to at least one wheel of an axle of a vehicle is provided. The method includes receiving at least one attribute signal indicating one or more attributes of the vehicle, determining a coupling state of the electric machine to at least one wheel of the axle depending on the at least one attribute signal, and outputting a coupling signal indicating the determined coupling state to control the coupling of the electric machine to at least one wheel of the axle, and the outputting includes delaying the output of the coupling signal indicating a change in the coupling state until a predetermined period has elapsed since the last change in the coupling state indicated by the coupling signal.

[0120] The predetermined period may be 30 seconds. The predetermined period may be 10 seconds. The change in the coupling state may be from a coupled state to an uncoupled state. The change in the coupling state may be a change from uncoupled to coupled.

[0121] At least one attribute signal may be composed of a speed signal indicating the speed of the vehicle. The at least one attribute signal may be composed of a driving mode signal indicating the driving mode of the vehicle.

[0122] An electromechanical control system for a vehicle includes one or more controllers, the vehicle comprising an electromechanical machine arranged to be selectively coupled to supply torque to at least one wheel of an axle of the vehicle, the electromechanical control system comprising one or more controllers, the control system comprising: input means for receiving a prohibition signal indicative of one or more prohibited coupling states; output means arranged to output a coupling signal for controlling the coupling of the electromechanical machine to at least one wheel of the axle; and processing means arranged to determine a coupling state of the electromechanical machine with respect to at least one wheel of the axle depending on the one or more prohibited coupling states, the processing means being arranged to control the output means to output a coupling signal indicative of the determined coupling state when the determined coupling state is not one of one or more suppressed coupling states. Advantageously, one or more inhibited coupling states can be prevented from being selected.

[0123] An electromechanical control system for a vehicle, the electromechanical control system including one or more controllers, the vehicle comprising an electromechanical machine arranged to be selectively coupled to supply torque to at least one wheel of an axle of the vehicle, the electromechanical control system comprising one or more controllers, the control system comprising input means for receiving at least one attribute signal indicative of one or more attributes of the vehicle and a prohibition signal indicative of one or more prohibited coupling states; output means arranged to output a coupling signal for controlling the coupling of the electromechanical machine to at least one wheel of the axle; and processing means arranged to determine a coupling state of the electromechanical machine with respect to at least one wheel of the axle depending on the at least one attribute signal and to compare the determined coupling state with the one or more prohibited coupling states, the processing means being arranged to control the output means to output a coupling signal indicative of the determined coupling state when the determined coupling state is not one of the one or more inhibited coupling states. Advantageously, selection of one or more inhibited coupling states can be prevented.

[0124] The processing means may be configured to assign a higher priority than the coupling state determined depending on the at least one attribute signal to one or more inhibited coupling states. Advantageously, one or more inhibited coupling states are prioritized.

[0125] One or more coupling states may include one or both of coupled and uncoupled. Advantageously, the coupling state may be coupled and / or uncoupled.

[0126] Optionally, one or more inhibited coupling states consist of one or both of coupled and uncoupled. Advantageously, one or both of the coupled state and the uncoupled state may be inhibited. The at least one attribute signal may consist of a speed signal indicative of the speed of the vehicle. Advantageously, the speed of the vehicle may be taken into account when determining the coupling state.

[0127] At least one attribute signal optionally includes a driving mode signal indicating the driving mode of the vehicle. Advantageously, the driving mode of the vehicle may be taken into account when determining the coupling state.

[0128] According to another aspect of the present invention, a powertrain including a system as described above is provided. According to yet another aspect of the present invention, a vehicle equipped with a control system as described above or a powertrain as described above is provided.

[0129] The electric machine may be configured to be selectively coupled to supply torque to at least one wheel of a first axle of the vehicle. The vehicle may include a second power source configured to provide torque to at least one wheel of a second axle of the vehicle. The second power source may be composed of a second electric machine.

[0130] According to a further aspect of the present invention, a method for controlling the coupling of an electric machine to provide torque to at least one wheel of an axle of a vehicle is provided. The method includes receiving at least one attribute signal indicating one or more attributes of the vehicle and a suppression signal indicating one or more suppressed coupling states, determining, depending on the at least one attribute signal, a coupling state of the electric machine to at least one wheel of the axle, comparing the determined coupling state with the one or more suppressed coupling states, and outputting a coupling signal indicating the determined coupling state and controlling the coupling of the electric machine to at least one wheel of the axle when the determined coupling state is not one of the one or more suppressed coupling states.

[0131] The method may include assigning a higher priority to one or more suppressed coupling states than to the coupling state determined depending on the at least one attribute signal.

[0132] One or more coupling states may be composed of coupled and uncoupled.

[0133] One or more inhibited coupling states optionally consist of one or both of coupled and uncoupled. At least one attribute signal may be composed of a speed signal indicative of the speed of the vehicle.

[0134] At least one attribute signal optionally consists of a driving mode signal indicative of the driving mode of the vehicle.

[0135] According to another aspect of the invention, an electromechanical control system for a vehicle is provided, the electromechanical control system comprising one or more controllers, the vehicle comprising an electromechanical selectively couplable to provide torque to at least one wheel of an axle of the vehicle, the control system comprising input means for receiving at least one signal indicative of a selection of a driving mode, output means configured to output a coupling signal for controlling the coupling of the electromechanical to at least one wheel of the axle, and processing means configured to determine a coupling state of the electromechanical to at least one wheel of the axle depending on the signal, the processing means being configured to control the output means to output a coupling signal indicative of the coupling state. Advantageously, the coupling state is determined according to the driving mode of the vehicle.

[0136] An electromechanical control system for a vehicle, the electromechanical control system including one or more controllers, the vehicle including an electromechanical machine configured to be selectively coupled to at least one wheel of an axle of the vehicle, the control system including input means for receiving at least one attribute signal indicative of one or more attributes of the vehicle and an efficiency signal indicative of a selection of an efficiency-based operating mode, and output means configured to output a coupling signal for controlling the coupling of the electromechanical machine to at least one wheel of the axle. Processing means configured to determine a first coupling state of the electromechanical machine to at least one wheel of the axle depending on the at least one attribute signal and a second coupling state of the electromechanical machine to at least one wheel of the axle depending on the at least one efficiency signal, the processing means controlling the output means to output a coupling signal indicative of the first and second coupling states if the same, and to output a coupling signal indicative of the first coupling state if the determined first and second coupling states are different. Advantageously, the coupling state is preferably determined according to a selection of a driving mode based on efficiency.

[0137] The processing means may be configured to assign a higher priority to the first coupling state than to the second coupling state. Advantageously, the coupling state is determined according to a priority order of one or more attributes.

[0138] One or more coupling states may optionally consist of coupled and uncoupled. Advantageously, the electromechanical machine may either be coupled to or disengaged from at least one wheel.

[0139] The at least one attribute signal may consist of a speed signal indicative of the speed of the vehicle. Advantageously, the first coupling state may be determined according to the speed of the vehicle.

[0140] According to another aspect of the invention, a powertrain is provided comprising a system as described above.

[0141] According to another aspect of the present invention, there is provided a vehicle comprising a control system as described above or a power train as described above.

[0142] The electric machine is optionally configured to be selectively coupled to provide torque to at least one wheel of a first axle of the vehicle, and the vehicle comprises a second source of power configured to provide torque to at least one wheel of a second axle of the vehicle. The second power source optionally includes a second electric machine.

[0143] According to a further aspect of the present invention, there is provided a method of controlling the coupling of an electric machine to provide torque to at least one wheel of an axle of a vehicle, the method comprising receiving at least one attribute signal indicative of one or more attributes of the vehicle and an efficiency signal indicative of a selection of an efficiency-based operating mode, determining a first coupling state of the electric machine to at least one wheel of the axle depending on the at least one attribute signal, determining a second coupling state of the electric machine to at least one wheel of the axle depending on the at least one efficiency signal, outputting a coupling signal indicative of the first and second coupling states if the same, and outputting a coupling signal indicative of the first coupling state if the determined first and second coupling states are different.

[0144] The method may include assigning a higher priority to the first coupling state than the second coupling state.

[0145] One or more coupling states may consist of coupled and uncoupled. The at least one attribute signal may consist of a speed signal indicative of the speed of the vehicle. The at least one attribute signal may consist of an operating mode signal indicative of the operating mode of the vehicle.

[0146] According to another aspect of the present invention, there is provided computer software configured to perform the method as described above when executed by a computer. The computer software may be stored on a computer-readable medium. The computer software may be stored prefixedly on a computer-readable medium.

[0147] Within the scope of the present application, it is explicitly intended that the various aspects, embodiments, examples and alternatives described in the previous paragraphs, claims and / or the following description and drawings, particularly their individual features, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, except where such features are incompatible. The applicant reserves the right to modify the originally filed claims, including the right to depend on and / or incorporate any feature of other claims, and / or to submit new claims accordingly, although not originally so claimed.

Brief Description of the Drawings

[0148] One or more embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings.

[0149]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Embodiments for Carrying Out the Invention

[0150] FIG. 1 is a diagram for explaining a vehicle 100 according to an embodiment of the present invention. The vehicle 100 provides space within the cabin of the vehicle 100 for one or more passengers. In some embodiments, the vehicle 100 may be manually driven by one of the passengers representing the driver of the vehicle 100, but the vehicle 100 may have at least partially autonomous driving capabilities in some embodiments. The vehicle 100 is at least partially electrically driven vehicle 100 comprising an internal combustion engine (engine) and one or more electromechanical or traction electric motors for supplying power, whereby the vehicle is a hybrid electric vehicle (HEV). In some embodiments, the vehicle 100 may be a battery electric vehicle (BEV) that moves entirely electrically, i.e., does not have an internal combustion engine.

[0151] FIG. 2 shows a system 20 for a parallel HEV 10. The system 20 at least partially defines the powertrain of the HEV. The system 20 includes a control system 208. The control system 208 has one or more controllers. The 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, and / or the like. The system 20 includes an engine 202. The engine 202 is an internal combustion engine. The illustrated engine 202 is an internal combustion engine. The illustrated engine 202 has three combustion chambers, but in other embodiments, a different number of combustion chambers may be provided.

[0152] The engine 202 is operably coupled to the control system 208 such that the control system 208 can control the output torque of the engine 202. The output torque of the engine 202 may be controlled by controlling one or more of the air-fuel ratio; spark timing; poppet valve lift; poppet valve timing; throttle opening; fuel pressure; turbocharger boost pressure; and / or the like, depending on the type of the engine 202.

[0153] System 20 includes a vehicle transmission structure 204 for receiving output torque from engine 202. The vehicle transmission structure 204 may comprise an automotive vehicle transmission or a semi-automatic vehicle transmission. The vehicle transmission structure 204 is composed of a fluid-coupled torque converter 217 between the engine 202 and a gear train.

[0154] 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 structure 204 as a transaxle or provided separately.

[0155] Engine 202 is mechanically connectable or linkable to a first set of vehicle wheels (FL, FR) via a first torque path 220. The first torque path 220 extends from the output of the engine 202 to the vehicle transmission structure 204, then to an axle / drive shaft, and then to the first set of vehicle wheels (FL, FR). In a vehicle overrun and / or friction braking situation, torque may flow from the first set of vehicle wheels (FL, FR) to the engine 202. The torque flow towards the first set of vehicle wheels (FL, FR) is positive torque, and the torque flow from the first set of vehicle wheels (FL, FR) is negative torque.

[0156] The illustrated first set of vehicle wheels (FL, FR) has front wheels and the axle is a front cross axle. Thus, system 20 is configured for front-wheel drive by engine 202. In another embodiment, the first set of vehicle wheels (FL, FR) has rear wheels (RL, RR). The illustrated first set of vehicle wheels for the vehicle (FL, FR) is a pair of vehicle wheels, but in other embodiments, a different number of vehicle wheels may be provided.

[0157] In the illustrated system 20, a longitudinal (central) drive shaft is not provided to secure space 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). Note that the engine 202 may be placed horizontally to save space.

[0158] A torque path connector 218, such as a clutch, is provided inside and / or outside the bell housing of the vehicle transmission structure 204. The clutch 218 is configured to connect and disconnect the torque path 220 between the engine 202 and the first set of vehicle wheels (FL, FR). The system 20 may be configured to automatically operate the clutch 218 without user intervention.

[0159] The 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 motors. The first electric traction motor 216 is disposed on the engine side of the clutch 218.

[0160] The first electric traction motor 216 may be mechanically coupled to the engine 202 via a belt or a chain. For example, the first electric traction motor 216 may be a belt integrated starter generator (BiSG). In the figure, the first electric traction motor 216 is disposed at the accessory drive end of the engine 202, which is on the opposite side of the vehicle transmission end of the engine 202. In an alternative example, the first electric traction motor 216 is a crankshaft integrated motor generator and is disposed at the vehicle transmission end of the engine 202.

[0161] The first electric traction motor 216 is configured to apply a positive torque and a negative torque to the crankshaft of the engine 202, for example, to increase the output torque of the engine 202, to stop (cut off) the engine 202 during stoppage or coasting, to start (start up) the engine 202, and to provide functions such as regenerative braking in the regenerative mode. In the hybrid electric vehicle mode, both the engine 202 and the first electric traction motor 216 are operable to supply positive torque simultaneously to increase the output torque. The first electric traction motor 216 may be capable of continuous all-electric driving, but in other embodiments, the first electric traction motor 216 may be capable of all-electric driving, particularly in embodiments without the engine 202. One or both of the engine 202 and the first electric traction motor 216 can provide torque to the first axle 221 of the vehicle.

[0162] However, when the torque path 220 between the engine 202 and the first set of vehicle wheels (FL, FR) is disconnected, the torque path 220 between the first electric traction motor 216 and the first set of vehicle wheels (FL, FR) is also disconnected.

[0163] FIG. 2 illustrates a second electric traction motor 212 configured to enable at least an electric vehicle mode consisting of all-electric driving. Although not necessarily in all examples, in some 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.

[0164] Even if the torque path 220 between the engine 202 and the first set of vehicle wheels (FL, FR) is disconnected by the clutch 218, since the second electric traction motor 212 is connected to at least one vehicle wheel, the vehicle 10 can be driven in the electric vehicle mode. The at least one vehicle wheel may be one or both of the rear wheels (RL, RR) of the vehicle 100 associated with the second axle 222 of the vehicle 100.

[0165] The illustrated second electric traction motor 212 is configured to provide torque to the illustrated second set of vehicle wheels (RL, RR) of the second axle 222 of the vehicle. The second set of vehicle wheels (RL, RR) consists of different vehicle wheels from the first set of vehicle wheels (FL, FR) of the vehicle. The illustrated second set of vehicle wheels (RL, RR) constitutes the rear wheels, and the second electric traction motor 212 is operable to supply torque to the rear wheels (RL, RR) via the rear transverse shaft forming the second axle 222. Thus, the vehicle 10 may be rear-wheel drive in the electric vehicle mode.

[0166] The control system 208 may be configured to disconnect the torque path 220 between the engine 202 and the first set of vehicle wheels (FL, FR) in the electric vehicle mode to reduce parasitic pumping energy losses. For example, the clutch 218 may be disengaged. In the example of FIG. 2, this means that the first electric traction motor 216 is also disconnected from the first set of vehicle wheels (FL, FR).

[0167] Another advantage of the second electric traction motor 212 is that the second electric traction motor 212 may be configured to be operable in the hybrid electric vehicle mode to enable four-wheel drive operation even without a center drive shaft.

[0168] The second electric traction motor 212 may be selectively coupled to one or both of the wheels RL, RR of the second axle 222. The coupling of the torque path between the second electric traction motor 212 and one or both of the wheels RL, RR of the second axle 222 may be achieved via a second clutch 219. The second clutch 219 may be controlled to open, such as 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 both of the wheels (RL, RR) of the second axle 222. In some embodiments, the second clutch 219 may be a dog clutch.

[0169] Thus, it is understood that the second electric traction motor 212 is configured to be selectively coupled to provide torque to at least one wheel (RL, RR) of an axle of the vehicle 100. In some embodiments, the vehicle 100 is configured to include another power source configured to provide torque to at least one wheel (FL, FR) of another axle of the vehicle 100. In the illustrated embodiment, the another power source is configured by another electromechanical machine 216 in the form of the first electric traction motor 216. The another power source may include an internal combustion engine 202 that can provide positive torque alone or in combination with the first electric traction motor 216 in some embodiments.

[0170] To store power for the electric traction motors 212, 216, the system 20 has a traction battery 200. The traction battery 200 provides the nominal voltage required by a power consumer such as an electric traction motor. If the electric traction motors 212, 216 operate at different voltages, a voltage converter such as a DC-DC converter (not shown) may be provided to convert the voltage.

[0171] The traction battery 200 may be a high voltage (HV) battery. The high voltage traction battery provides a nominal voltage in the hundreds of volts, in contrast to a traction battery for a mild HEV that provides a nominal voltage in the tens of volts. The traction battery 200 may have a voltage and capacity to support continuous distance electric-only driving. The traction battery 200 may have a capacity in the kilowatt-hours to maximize the cruising range. The capacity may be in the tens of kilowatt-hours or in the hundreds of kilowatt-hours.

[0172] Although the traction battery 200 is illustrated as one entity, the functions of the traction battery 200 may be implemented using a plurality of small traction batteries located at different locations on the vehicle 10.

[0173] 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 (mild) electric traction motor 216 with a high-capacity battery (tens to hundreds of kilowatt-hours), the first electric traction motor 216 may be able to provide the functionality of the methods described herein not for short bursts but continuously. In another example, the electric traction motors 212, 216 may be paired with different traction batteries.

[0174] Finally, the illustrated system 20 is composed of one or more inverters. Two inverters 210, 214 are shown, one for each electric traction motor 212, 216. In other embodiments, one inverter or more than two inverters may be provided.

[0175] It can be understood from the above that the vehicle 100 can be provided with torque of power from a combination of sources. Embodiments of the present invention relate to determining which of the sources of motive torque to utilize.

[0176] FIG. 3 is a diagram showing a control system 300 according to an embodiment of the present invention. The control system 300 may be formed by one or more controllers 305. It will be understood that the control system 300 illustrated in FIG. 2 is merely exemplary, but has one electronic controller 305. The controller 305, or each controller 305, includes processing means 310 and storage means 320. The processing means 310 may be one or more electronic processors 310 or a processing device 310 such as a CPU for executing computer-readable instructions. The storage means 320 may be one or more memory devices 320. The one or more memory devices 320 may store computer-readable instructions for execution by at least one processing device 310.

[0177] The controller 305 comprises an input means 330 and an output means 340. The input means 330 is configured to receive one or more signals 335. The input means 330 may be an electrical input to the controller 305 for receiving one or more electrical signals 335. The output means 340 outputs at least one signal 345 provided to one or both of the second clutch 219 and the second electric traction motor 212 in FIG. 3, and is configured to control the coupling to the second torque path to provide torque to one or both of the wheels of the second axle 222. The output means 340 is an electrical output of the controller 305. The output means 340 is operable by the processing device 310 to output the signal 345 under its control. The signal 345 can "spin up" or accelerate the second electric traction motor 212 to a rotational speed suitable for coupling to the second axle 222, that is, the vehicle 100 may be moving through the torque provided by the first electric traction motor 216 and / or the engine 202. The signal 345 may cause the closing of the second clutch 219 to couple the second electric traction motor 212 to the second torque path.

[0178] The electrical input 330 and output 340 of the controller 305 may be provided to / from a vehicle communication bus or network, such as a CANBus or other communication network. This may be implemented by, for example, an Internet Protocol (IP)-based network such as Ethernet, or the FlexRay or Single Edge Nibble Transmission (SENT) protocol, although other protocols may be used.

[0179] FIG. 4 is a diagram schematically showing a part of the controller 305 that constitutes the input means 330 and the output means 340 of the system 300. FIG. 4 shows inputs 410, 420, 430, 440, 450, 460, 470 to the input means 330 of the controller 305 that form the signal 335 illustrated in FIG. 3. FIG. 4 further illustrates modules 510, 520, 530, 540, 550, 560, 570, or functional units, which can be operably executed on the processing device 310 of the controller 305. Each of the inputs 410, 420, 430, 440, 450, 460, 470 provides information related to one or more aspects or attributes of the vehicle 100 or its powertrain 20.

[0180] The inputs 410, 420, 430, 440, 450, 460, 470 can include one of one or more speed signals 410, temperature signals 420, fault-derived coupling state request (FDCSR) signals 430, driving mode (DM) signals 440, state of charge (SoC) signals 450, and inhibition signals 460 that provide information or data by which a desired coupling state is determined by one or more of the modules 510, 520, 530, 540, 550, 560, 570. The desired coupling state is the desired coupling of the torque path between the second electric traction motor 212 and one or both of the wheels RL, RR of the second axle 222 of the vehicle 100, which is determined by one or more of the modules 510, 520, 530, 540, 550, 560, 570.

[0181] One or more speed signals 410 indicate one or more of the speed of the vehicle 100, i.e., the speed of the vehicle 100 on the ground, a wheel speed signal indicating the rotational speed of one or more wheels of the vehicle, and a motor speed signal indicating the speed of one or both of the first and second electric traction motors 216, 212.

[0182] The temperature signal 420 indicates one or more of the ambient temperature, the temperature of one or more units of the vehicle 100, or the temperature of a fluid associated with one or more units, particularly the coolant fluid used for cooling the units. For example, the coolant fluid may be the coolant fluid for one or both of the traction electric motors 212, 216. In some embodiments, the 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 one or more of the temperature of one or both of the inverters 210, 214, the temperature of one or both of the 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 capability of the traction battery 200, which is a function of the temperature and the state of charge (SoC) of the traction battery 200. Thus, in some embodiments, the temperature signal 420 may include a signal indicating the power capability of the traction battery 200, which is an indication of temperature.

[0183] The fault-derived coupling state request signal (FDCSR) 430 indicates a request for a coupling state derived in the determination of a fault associated with the vehicle 100, such as a fault associated with the powertrain. For example, if a fault associated with the second clutch 219 is detected by a fault management module (not shown), the fault management module may request a coupled or uncoupled state to control the state of the clutch 219, i.e., open or closed, to manage or resolve the fault. Other faults may be evaluated to cause a desired coupling state to manage or improve the fault. In some embodiments, the fault management module 530 may be executed on the processing device 310, and thus, the FDSCR signal 430 may be generated inside the controller 305.

[0184] The driving mode signal 440 may be automatically determined by an autonomous driving controller such as an intelligent driving mode or terrain response (TR) determination unit, an ADAS system, or may be selected by an occupant of the vehicle 100, and may indicate the driving mode of the vehicle 100. The driving mode signal 440 may indicate an efficiency-based driving mode, i.e., providing minimum fuel and / or energy usage, a four-wheel drive driving mode in which the number of drive wheels can be automatically selected, and a selected driving gear, i.e., a selection such as neutral, drive (D), reverse (R), etc.

[0185] The state of charge (SoC) signal 450 indicates the SoC of the traction battery 200.

[0186] The inhibit signal 460 indicates one or more inhibited coupling states. For example, the inhibit signal 460 may indicate that the coupling state is prohibited to prevent the coupling of the second electric traction motor 212 to one or both wheels (RL, RR) of the second axle 222, or that the decoupling state is prohibited to prevent the decoupling of the second electric traction motor 212 from one or both wheels (RL, RR) of the second axle 222.

[0187] The inputs 410, 420, 430, 440, 450, 460, 470 include, in some embodiments, a coupling state signal 470 that indicates the actual coupling state of the second electric traction motor 212 to one or both wheels of the second axle 222. In some embodiments, the coupling state signal 470 has coupling and non-coupling states indicating each coupling. The coupling state 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 that the coupling or disconnection of the second electric traction motor 212 has been successful.

[0188] In some embodiments, modules 510, 520, 530, 540, 550, 560, 570 include a high-speed module 510, a low-speed module 520, a fault management module (FMM) 530, an anti-noise module 540, a prohibition module 550, a driving mode module (DMM) 560, and an arbiter 570. Not all modules are present in all embodiments, and thus it is understood that embodiments of the present invention may include one or more of the aforementioned modules. Each module will be described below. Each of the high-speed module 510, the low-speed module 520, the fault management module 530, the anti-noise module 540, the suppression module 550, and the efficiency module 560 may determine its respective desired coupling state so as to be present in the relevant embodiments. An indication of the desired coupling state is provided to the arbiter 570 and is determined as the determined coupling state, i.e., for determining the coupling state of the electromechanical machine 212 to the axle 222 of the vehicle.

[0189] Next, an embodiment of the high-speed module (HSM) 510 will be described with reference to FIGS. 5 and 6. The HSM 510 is operably executable by the processing device 310 to determine the coupling state of the electromechanical machine 212 to at least one wheel of the axle 222 depending on the speed signal 410 indicating the speed of the vehicle 100. In some embodiments, the HSM 510 and the arbiter 570 are configured to output a coupling signal 345 to the controller 305 to control the coupling of the second electric traction machine 212 to at least one wheel of the axle 222 depending on the speed signal 410 as described. The HSM 510 is configured to cause the disconnection of the second electric traction motor 212 from at least one wheel of the axle 222 at high speeds of the vehicle 100, which advantageously prevents the rotation of the second electric traction motor 212 at excessive speeds that could damage the second electric traction motor 212.

[0190] FIG. 5 is a diagram showing a method 600 according to an embodiment of the present invention that can be executed by an HSM 510 executed by a processing device 310 of a controller 305. The method 600 will be described with reference to FIG. 6 that illustrates the speed of the vehicle 100 indicated by a speed signal 410 over a certain period. Also shown at the bottom of FIG. 6 is a desired coupling signal 515 output by the HSM 510, representing requests 730, 740 for a desired coupling state from the HSM 510 determined depending on the speed signal 410.

[0191] The method 600 includes, at the HSM 510, a step 610 of receiving one or more signals, such as data representing one or more signals. In the illustrated embodiment, the HSM 510 is configured to receive a speed signal 410 that can indicate the speed of the vehicle 100 as described above. In some embodiments, the HSM 510 is configured to receive a temperature signal 420 as described above. In some embodiments, the HSM 510 is configured to receive an SoC signal 460 indicating the state of charge of one or more traction batteries 200 for supplying power to the traction electric machines 212, 216. In some embodiments, the HSM 510 may receive a signal indicating the power limit or capacity of the traction battery 200, indicating the temperature of the traction battery 200, as described above.

[0192] Step 620 includes determining a desired coupling state of the second electric traction motor 212 for at least one wheel (RL, RR) of the second axle 222 depending on the speed signal 410. Step 620 determines whether the speed of the vehicle 100 is greater than or equal to a first high speed threshold 710 shown in FIG. 6. Thus, step 620 includes comparing the speed of the vehicle 100 with one or more thresholds 710, 720. The one or more thresholds 710, 720 have a first high speed threshold 710. In some embodiments, the one or more thresholds 710, 720 have a second high speed threshold 720. The second high speed threshold 720 represents a vehicle speed lower than the first high speed threshold 710. The first high speed threshold 710 and the second high speed threshold 720 are illustrated in FIG. 6.

[0193] If the speed of the vehicle 100 is equal to or greater than the first high-speed threshold 710, the method 600 proceeds to step 630. However, if the speed of the vehicle 100 is less than the first high-speed threshold 710, the method 600 proceeds to step 640.

[0194] In the example of FIG. 6, the method 600 proceeds to step 640 before time t1. As understood, before time t1, the vehicle 100 is generally accelerating, which may be caused by the positive torque applied by the first electric traction motor 216 and / or the engine 202, and the second electric traction motor 212 coupled to the second torque path via the second axle 222.

[0195] In step 630, depending on the speed signal 410 indicating a vehicle speed equal to or greater than the first high-speed threshold 710, the desired coupling state is determined to be uncoupled. In step 630, the HSM 510 may output to the arbiter 570 an indication 515 that the desired coupling state, which indicates a request 740 to disconnect the second electric traction motor 212 from the second axle 222, is disengaged. The indication 515 of the desired coupling state of the decoupling 740 may be referred to as a high-speed coupling state request 515, 740. The arbiter 570 may mediate among multiple requests for the desired coupling state, as described in some embodiments. In the absence of other competing requests from other modules, the arbiter 570 is configured to output, via the output means 340, the high-speed coupling state request 515 for the uncoupled state 740 as an output signal 345. In some embodiments, the high-speed coupling state request 515 may be provided directly from the HSM 510 to the output means 340 of the controller 305.

[0196] After time t1, that is, when the speed of vehicle 100 exceeds the first high-speed threshold 710, it is determined that it is desirable to disconnect the second electric traction motor 212. By continuing to connect the second electric traction motor 212 to the wheel(s) of vehicle 100, the second electric traction motor 212 will exceed a predetermined rotational speed. The predetermined rotational speed may be a motor speed of 12,000 rpm, but it is understood that other predetermined rotational speeds may be selected. The predetermined rotational speed may correspond to a vehicle speed of 140 km / h, but it is understood that this depends on the gears between the second electric traction motor 212 and the wheels of vehicle 100 and the diameter of the wheels. Further, in some embodiments, as described with reference to FIG. 7, the vehicle speed corresponding to the first high-speed threshold 710, and thus the rotational speed of the second electric traction motor 212, may be determined depending on the temperature.

[0197] The output means 340 of the controller 305 is configured to output coupling signals 345, 730, 740 indicating a request 740 to disconnect the second electric traction motor 212 from at least one wheel of the second axle 222 depending on the desired coupling state being released.

[0198] In step 620, if the speed of vehicle 100 is less than the first high-speed threshold 710, the method proceeds to step 640. In step 640, it is determined whether the speed of vehicle 100 is less than or equal to a 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.

[0199] In step 660, HSM 510 is configured not to require a desired engagement state of the second electric machine 212. HSM 510 may output a request for an engagement state to arbiter 570, or as shown in FIG. 5, may output a "no request" signal 730 to arbiter 570, where the no request signal 730 indicates that HSM 510 does not require a particular engagement state of the second electric traction machine 212 to one or more wheels of the second axle 222. Thus, prior to time t1 in FIG. 6, HSM 510 may output a no request signal 730 to arbiter 570, or in other embodiments may not output a signal to arbiter 570. Arbiter 570 may have a default engagement state. The default engagement state may be engaged, i.e., such that the second electric traction motor 212 is coupled to the torque path of the second axle 222. Thus, when either the "no request" signal 730 or a no request signal is received by arbiter 570, arbiter 570 may output a coupling request determined via output means 340.

[0200] In some embodiments, HSM 510 is configured 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 is understood that HSM 510 may request a default state of engagement in some embodiments when the speed signal 410 indicates a low vehicle speed.

[0201] In some embodiments, the HSM 510 may apply hysteresis to the speed signal 410 to determine the coupling state. That is, the decoupled coupling state may be determined for vehicle speeds greater than a second high speed threshold 720, i.e., greater than when the second electric traction motor 212 is re-coupled to the torque path via the second axle 222. Advantageously, this helps prevent “hunting” or “flickering” between the uncoupled and coupled states as the vehicle speed varies around (above and below) the first high speed threshold 710. The use of the second high speed threshold 720 provides hysteresis in some embodiments. As can be understood from FIG. 6, between t1 and prior to time t2, the vehicle decelerates from the peak speed and the speed signal 410 falls below the first high speed threshold 710. As can be understood from the lower part of FIG. 6, the “no request” signal 730 is not immediately output when the speed of the vehicle 100 falls below the first high speed threshold 710.

[0202] Instead, in the region between the first and second high speed thresholds 710, 720, the decoupled 740 coupling state is maintained until the vehicle speed falls below the second high speed threshold 720. At step 650 reached when the vehicle speed is between the first and second high speed thresholds 710, 720, the desired coupling state is determined depending on the speed signal 410, depending on which of the first and second high speed thresholds 710, 720 was last crossed. Thus, prior to time t2 when the speed signal 410 falls below the first high speed threshold 710, the coupling state is determined as decoupled at step 650 based on the last crossing of the first high speed threshold 710. Thus, the method proceeds to step 630. Similarly, prior to time t1, when the speed signal 410 exceeds the second high speed threshold 720, the method proceeds to step 660 and the “no request” output signal 730 is maintained such that the arbiter 570 in the exemplary embodiment determines the coupling state as coupled.

[0203] It can thus be understood that embodiments of the present invention select the coupling of the second electric traction motor 212 depending on the speed of the vehicle 100.

[0204] FIG. 7 is a diagram showing the motor speed with respect to temperature according to an embodiment of the present invention, that is, the speed (RPM) of the second electric traction motor 121. Illustrated in FIG. 7 is a first high speed threshold 710 that varies depending on temperature according to some embodiments of the present invention. As described above, in some embodiments of the present invention, the controller 305 receives the temperature signal 420. In some embodiments, the first high speed threshold 710 adopts a first value 710 between the first and second temperatures 740, 750. The first temperature 740 at which one or both of the first and second high speed thresholds 710, 720 decrease may correspond to a temperature of 0° C. or lower, for example, a low temperature such as -5° C., but other temperatures may be selected. Although not shown, it is understood that the second high speed threshold 720 may follow the first high speed threshold 710.

[0205] Below the first temperature 740, in some embodiments, as shown, the first high speed threshold 710 is determined such that the coupling state of the second electric traction motor 212 is in a low speed and uncoupled state, that is, it decreases to the value 810. In some embodiments, one or both of the first and second high speed thresholds 710, 720 may decrease proportionally to temperature between one or more temperature ranges. Advantageously, the decrease in the first high speed threshold 710, 810 allows for changes in the coolant of the second electric traction motor 212, or the low viscosity fluid associated with the second torque path via the second axle 222, such that the rotation of the motor 212 consumes more energy and the low speed decoupling is more efficient. In the embodiment shown in FIG. 7, the first high speed thresholds 710, 810 are configured to decrease depending on temperature over the first temperature ranges 740, 730. The temperature range may be between -10° C. and -20° C., but other temperature ranges may be selected. In other embodiments, the first high speed threshold 710 may decrease instantaneously, but advantageously, having a gradual change may be less noticeable to the occupants of the vehicle 100. Below the third temperature 730, the first high speed threshold 810 corresponds to the minimum threshold speed 810.

[0206] Similarly, in some embodiments, above the second temperature 750, the first high speed threshold 710 is configured to decrease in a temperature-dependent manner from the second temperature range 750, 760 to the fourth temperature 760. Above the fourth temperature 760, the first high speed threshold 710 adopts a constant value 820 in some embodiments, which may be different from the minimum threshold speed 810 as shown in FIG. 7, although in other embodiments the two speeds 810, 820 may be equal. Advantageously, the decrease in the first high speed thresholds 710, 820 at higher speeds can reduce cooling problems associated with the second electric traction motor 212. The temperature 750 may be at least 25° C. or at least 35° C., for example, in some embodiments, a temperature between 50° C. and 60° C.

[0207] As described above, in some embodiments, the controller 305 is configured to receive the SoC signal 450. In some embodiments, one or both of the first high-speed threshold 710 and the second high-speed threshold 720 are determined depending on the SoC of the traction battery 200. As described above, in some embodiments, the arbiter 570 may be configured to achieve a combined default coupled state when there is no uncoupled state request from the HSM 510. In this way, the HSM 510 and the arbiter 570 operate to uncouple the second electric traction motor 212 when the speed of the vehicle 100 is greater than or equal to the first high-speed threshold 710 and to couple it when the speed of the vehicle 100 is less than 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 be "spun up" or accelerated from a low rotational speed, such as zero, to the rotational speed of the rear axle 222 before the second clutch 219 can be closed to couple the second electric traction motor 212 to the axle 222. As can be understood, accelerating the second electric traction motor 212 consumes energy from the traction battery 200. If the vehicle 100 is operable with a traction battery 200 having a low SoC, one or both of the first high-speed threshold 710 and the second high-speed threshold 720 may be reduced depending on the SoC. Advantageously, 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 be "spun up" to a low rotational speed to recouple to the second axle 222, thereby requiring less energy consumption when the traction battery 200 has a low SoC.

[0208] Next, an embodiment of the low-speed module (LSM) 520 will be described with reference to FIGS. 8 and 9. The LSM 520 is operably executable by the processing device 310 to determine the coupling state of the electromechanical machine 212 to at least one wheel of the second axle 222 depending on the speed signal 410 indicating the speed of the vehicle 100. In some embodiments, the LSM 510 and the arbiter 570 are configured to output a coupling signal 345 to the controller 305 to control the coupling of the electromechanical machine 212 to at least one wheel of the second axle 222 depending on the speed signal 410 as described. As described, the LSM 520 is configured to cause the coupling of the electromechanical machine 212 to at least one wheel of the axle 222 to occur at a low speed, which advantageously enables the electromechanical machine 212 to provide motive torque to the vehicle at a low speed, particularly from a stationary state. Further, the LSM 520 is configured to control the coupling of the electromechanical machine to avoid or reduce undesirable characteristics that may be prominent for the occupants of the vehicle 100 as described.

[0209] FIG. 9 is a diagram showing a method 1000 according to an embodiment of the present invention that can be executed by the LSM 520 executed by the processing device 310 of the controller 305. The method 1000 will be described with reference to FIG. 8 that illustrates the speed of the vehicle 100 indicated by the speed signal 410 over a certain period. Also shown at the bottom of FIG. 8 is the desired coupling signal 525 output by the LSM 520, representing the requests 730, 750 for the desired coupling state from the LSM 520 determined depending on the speed signal 410.

[0210] The method 1000 includes, in the LSM 520, a step 1010 of receiving one or more signals, such as data representing one or more signals. In the illustrated embodiment, the LSM 520 is configured to receive a speed signal 410 indicating the speed of the vehicle 100.

[0211] Step 1020 includes determining a desired engagement state of the second electric traction motor 212 for at least one wheel (RL, RR) of the second axle 222 depending on the speed signal 410. Step 1020 includes determining whether the speed of the vehicle 100 is equal to or below a first low speed threshold (LST) 910. Thus, step 1020 includes comparing the speed of the vehicle 100 with one or more thresholds 910, 920, and the one or more thresholds 910, 920 have a first LST 910. In some embodiments, the one or more low speed thresholds 910, 920 include a second LST 920 as shown in FIG. 8. The second LST 920 represents a vehicle speed greater than the first LST 910. FIG. 8 shows the first LST 910 and the second LST 920.

[0212] In step 1030, depending on the speed signal 410 indicating a vehicle speed equal to or below the first LST 910, the desired engagement state is determined to be engaged. In step 1030, the LSM 520 may output an indication 525 of the desired engaged engagement state indicating a request 750 to couple the second electric traction motor 212 to the second axle 222 to the arbiter 570. The indication 525 of the desired engaged engagement state may be referred to as a low speed engagement state request 525, 750. The arbiter 570 may, in some embodiments, arbitrate between multiple requests for the desired engagement state 750. In the absence of competing requests from other modules, the arbiter 570 is configured to output the low speed engagement state request 525 for the engagement state 750 as an output signal 345 via the output means 340. In some embodiments, the low speed engagement state requests 525, 750 may be provided directly from the LSM 520 to the output means 340 of the controller 305.

[0213] Referring to FIG. 8, after time t3, that is, when the speed of the vehicle 100 is equal to or less than the first LST 910, it is determined that it is desirable to couple the second electric traction motor 212. For example, it can be assumed that the vehicle 100 is about to stop and the torque from the second electric traction motor 212 is useful for, for example, starting from a standstill. It is understood that a predetermined vehicle speed corresponding to the first LST 910 can be selected, and it may be a vehicle speed of 10 km / h. In some embodiments, the vehicle speed corresponding to the first LST 910 may be selected or determined based on the deceleration of the vehicle 100, which may be determined based on the rate of change of the vehicle speed signal 410. In the case of a large deceleration, that is, when the deceleration threshold is exceeded, the vehicle speed corresponding to the first LST 910 may be increased to advantageously enable the connection of the second electric traction motor 212 before the vehicle 100 stops.

[0214] The output means 340 of the controller 305 is configured to output a coupling signal 345, 750 indicating a request to couple the second electric traction motor 212 to at least one wheel of the second axle 222, depending on whether the desired coupling state is engaged, as in step 1030.

[0215] In some embodiments, as shown in Table 1 below, due to the default state being coupled, the coupling request 750 shown in FIG. 8 output as a result of the vehicle speed decreasing via the LST910 has no practical effect (change in state) because the second electric traction motor 212 is already coupled to the second axle 222 as a result of the default state being coupled. However, in some embodiments, when the vehicle speed decreases through the LST910, the second electric traction motor 212 is decoupled from the second axle 222. In such a situation, the arbiter 570 may determine the arbitration-coupled state regarding the LTS910 depending on the reason for the decoupling of the second electric traction motor 212. While the vehicle speed is above the LST910, if the arbitration-coupled state is decoupled for a high-priority reason such as a fault, the arbiter 570 will not change the arbitration-coupled state to coupled in response to the coupling request 750 from the LSM520. However, if the reason for the uncoupled state is a low-priority reason etc., the arbiter 570 can change the mediation-coupled state to a coupled state in response to the coupling request 750 from the LSM520.

[0216] In step 1020, if the speed of the vehicle 100 is greater than the first LST910, the method proceeds to step 1040. In step 1040, it is determined whether the speed of the vehicle 100 is greater than or equal to the second LST920. If the speed of the vehicle is greater than or equal to the second LST920, the method proceeds to step 1060.

[0217] In step 1060, the LSM520 is configured not to require a desired coupling state of the second electric machine 212. The LSM520 may output a request for a coupling state to the arbiter 570 and, as shown in FIG. 8, output a "no request" signal 730 to the arbiter 570. The no request signal 730 indicates that the LSM520 does not require a specific coupling state of the second electric traction machine 212 to one or more wheels of the second axle 222. Thus, prior to time t3 in FIG. 8, the LSM520 may output a no request signal 730 to the arbiter 570 or, in other embodiments, may not output a signal to the arbiter 570. The arbiter 570 may have a default coupling state. The default coupling state may be such that the second electric traction motor 212 is coupled to the torque path of the second axle 222, i.e., it may be coupled. Thus, when either the "no request" signal 730 or a no request signal is received by the arbiter 570, the arbiter 570 may output a coupling request determined via the output means 340.

[0218] In some embodiments, the LSM520 is configured 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. The LSM520 is understood to require a coupled default state in some embodiments when the speed signal 410 indicates a low vehicle speed, i.e., less than the first LST910.

[0219] In some embodiments, the LSM520 may apply hysteresis to the speed signal 410 to determine the engagement state. That is, the engaged engagement state may be determined for vehicle speeds greater than the vehicle speed at which it is determined that the second electric traction motor 212 is coupled to the torque path via the second axle 222, i.e., for vehicle speeds higher than the first LST910. Advantageously, this helps prevent "hunting" or "flickering" between the disengaged and engaged states when the vehicle speed changes around (above and below) the first LST910. The use of the second LST920 provides hysteresis in some embodiments. As can be understood from FIG. 8, between t3 and before time t4, the vehicle accelerates from the minimum speed such that the speed signal 410 exceeds the first LST910 during the period before time t4. As can be understood from the lower part of FIG. 8, the "no demand" signal 730 is not immediately output when the speed of the vehicle 100 exceeds the first LST910, i.e., the engagement 750 is maintained.

[0220] Instead, in the region between the first and second LSTs 910, 920, the engaged state of the engagement 750 is maintained until the vehicle speed decreases and crosses the second LST920 at time t4. At step 1050 reached when the vehicle speed is between the first and second LSTs 910, 920, the desired engagement state is determined depending on the speed signal 410, depending on which of the first and second LSTs 910, 920 was last crossed. Thus, before time t4 when the speed signal 410 falls below the second LST920, the engagement state is determined to be engaged at step 1050 based on the last crossing of the first LST910. Similarly, immediately before time t3, when the speed signal 410 is above the first LST920, the "no demand" output signal 730 is maintained because the last crossed threshold is the second LST920.

[0221] As can be understood from FIG. 8, some embodiments of the LSM520 are configured to include a third LST930. When the vehicle speed 410 is less than or equal to the third LST930, if it is not properly coupled to the second torque path via the second axle 222, the coupling of the motor 212 is prohibited. The third LST930 may correspond to a speed of, for example, 5 km / h, although other speeds may be selected.

[0222] In some embodiments, the LSM520 is configured to receive a signal indicating the coupling state 470 of the second electric traction motor 212 to at least one wheel of the axle 222. The signal 470 reports whether the second electric traction motor 212 is properly coupled to at least one wheel of the axle 222. In some situations, the coupling state is determined to be coupled and a corresponding request is output by the controller 305. However, due to electrical and / or mechanical reasons, it may not be possible to couple the motor 212 to the second torque path, at least immediately. For example, the second clutch 219 may not yet have successfully engaged the drive output of the motor 212 to the axle 222. In particular, it may be difficult to successfully couple the motor 212 when the vehicle is moving slowly or is stationary. Further, attempts to couple the motor 212 to the axle may become increasingly prominent to the occupants of the vehicle 100 in the form of noise and / or vibration, etc., and may cause damage if attempted while stationary. The use of the third LST930 reduces such risks.

[0223] In some embodiments, the LSM520 determines a coupling prohibited state. In some embodiments, the LSM520 outputs a coupling prohibition signal 526 in a coupling prohibited state where the speed signal 410 indicates a vehicle speed equal to or less than that of the third LST930. The LSM520 may output the coupling prohibition signal 526 when the vehicle speed is less than or equal to the third LST930 and the coupling state signal 470 indicates that the second electric traction motor 212 is disconnected from the second axle 222, that is, when the coupling success due to the vehicle speed being less than or equal to the first LST910 has not yet occurred.

[0224] In some embodiments, the LSM520 may apply hysteresis to the speed signal 410 to determine the coupling prohibited state. That is, the coupling prohibited state may be determined for vehicle speeds greater than that of the third LST930. Advantageously, this helps to prevent "hunting" or "flickering" between the uncoupled state and the coupled state when the vehicle speed changes around (above and below) the third LST930. As shown in FIG. 9, the use of the fourth LST950 provides hysteresis in some embodiments. The fourth LST950 defines the maximum speed of a coupling prohibited region 940 that defines the coupling prohibited state. The third and fourth LST930, 950 act as described above with respect to the first and second LST910, 920 and the speed signal 410.

[0225] Some embodiments of the present invention include a Fault Management Module (FMM) 530. The FMM 530 is configured to determine a desired coupling state of the second electric traction motor 212 with respect to at least one wheel (RL, RR) of the second axle 222 depending 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 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 configured to determine that the coupling state is uncoupled in order to deactivate the second electric traction motor 212 and cool the inverter for a certain period of time. In another example, the FMM 530 is configured to receive the coupling state signal 470 described above. The coupling state signal 470 may indicate that the attempt to disconnect the second electric traction motor 212 from the axle has failed. Thus, the FMM 530 determines that it is coupled to the coupling state depending thereon to reduce problems associated with the problematic uncoupled state. The FMM 530 is configured to output a Fault Derived Coupling State Request (FDCSR) signal 535 depending on one or more received signals indicating a fault state associated with the vehicle 100. The FDCSR signal 535 indicates a coupling state request determined by the FMM 530 in response to one or more faults, undesirable states, or parameters associated with the vehicle. The FDCSR signal 535 is received by an arbiter 570 in some embodiments, as shown in FIG. 4.

[0226] In some embodiments, if the FMM530 fails to properly change the engagement state, it is configured to manage a retry of changing the engagement state of the second electric traction motor 212, i.e., a further attempt. In particular, in some embodiments, the FMM530 is configured to control the output means 340 of the controller 305 to output a signal 345 indicating a retry of changing the engagement state of the second electric traction motor 212, i.e., to request a further attempt, as described.

[0227] FIG. 11 is a diagram showing a method 1200 according to an embodiment of the present invention. The method 1200 is a method for managing a retry of a change in the engagement state of the second electric traction motor 212.

[0228] In step 1210, the engagement state of the second electric traction motor 212 is determined. The engagement state may be determined by one of the modules 510 - 560 and the engagement state request signal as a result received by the arbiter 570, or by the arbiter 570 in the case of a default engagement state when there is no request from the modules 510 - 560.

[0229] In step 1220, an engagement state request signal 345 for requesting the determined coupling state is output from the controller 305 via the output means 340. For example, the engagement state request may request either an engaged state or a disengaged state of the second electric traction machine 212 with respect to the second axle 222.

[0230] In step 1230, the FMM 530 is configured to determine whether the attempt to change the coupling state of the second electric traction motor 212 to the second axle 222 has ended in failure. As described above, the coupling state signal 470 indicates the actual coupling state of the second electric traction motor 212 to one or both wheels of the second axle 222. Therefore, the FMM 530 can determine, depending on the coupling state signal 470, whether a failure has occurred, i.e., whether the actual coupling state reflects the required coupling state. Step 1230 may be executed after a delay to allow a change in the coupling state to be performed, such as the second clutch 219 being opened or closed. If the change in the coupling state is successful, the method returns to step 1210. However, if the change is not successful, i.e., if a failure in changing the coupling state of the second electric traction motor 212 occurs as indicated by the coupling state signal 470, the method proceeds to step 1240.

[0231] In step 1240, the speed of the vehicle 100 is determined. Step 1240 consists of receiving a speed signal 410 indicative of the speed of the vehicle 100. Controlling the output means 340 of the controller 305 to output a coupling signal 345 indicative of a retry of the change in the coupling state is performed depending on the speed signal 410, as will be explained.

[0232] In some embodiments, the FMM 530 is configured to delay the control of the output means 340 for outputting a coupling signal 345 indicating a retry of a change in the coupling state, depending on the speed signal 410 indicating that the speed of the vehicle 100 is at least a predetermined minimum speed. The predetermined minimum speed may be, for example, a speed greater than substantially 0 km / h. It is understood that other predetermined minimum speeds may be, for example, 5 km / h, but other minimum speeds may be selected. Advantageously, preventing a retry of a change in the coupling state, particularly a change from uncoupled to coupled, at too low a vehicle speed can prevent the retry of the engagement of the second electric traction motor 212 with the axle from being noticed by the occupants of the vehicle 100. For example, in the case where (but not exclusively) the second clutch 219 is a dog clutch, attempting a retry may cause noise and / or vibration at low vehicle speeds.

[0233] In some embodiments, the FMM 530 is configured to delay controlling the output means 345 to output a coupling signal 345 indicating a retry of a change in the coupling state, depending on a speed signal indicating that the speed of the vehicle 100 is less than a maximum speed. The maximum speed may be, for example, a maximum of 50 km / h or a maximum of 30 km / h or a maximum of 20 km / h, although other maximum speeds may be selected. As described above, in order to couple the second electric traction motor 212 to the second axle 222, it may be necessary to "spin up" or accelerate the motor 212 to about the rotational speed of the axle 222. Advantageously, the maximum speed prevents or reduces the energy used when coupling the motor 212 to the axle 222. Furthermore, changing from an uncoupled state to a coupled state at a vehicle speed below the maximum speed can avoid attempting to couple the second electric traction motor 212 to the axle during a large deceleration period where it may be difficult to match the rotational speed of the second electric traction motor 212 to the axle 222, i.e., during hard braking or other deceleration of the vehicle 100. Accordingly, the FMM 530 delays controlling the output means 340 to output a coupling signal 345 indicating a retry of a change in the coupling state, depending on the speed signal 410 indicating that the speed of the vehicle is below a predetermined maximum speed.

[0234] In step 1250, the FMM 530 is configured to output a signal 535 indicating that if the speed of the vehicle 100 is above the minimum speed or above the minimum speed and less than the maximum speed considered in step 1240, a retry of the change in the coupled state is requested. The signal 535 may be a further request regarding the change in the coupled state, such as a request for one of the coupled state or the uncoupled state. This request may be received by an arbiter 570 that outputs a corresponding request or signal 345 via the output means 340 to cause a retry of the change in the coupled state. When a retry of the change is requested, the method returns to step 1230, where it is considered whether the retry was successful.

[0235] In some embodiments, a counter is maintained for each iteration of step 1250 to track the number of retries of the change in the coupled state. The FMM 350 in some embodiments is configured to attempt retries up to a predetermined maximum number. That is, to execute step 1250 up to the maximum number. The maximum number may be 5, 3, or 2 in some embodiments. Advantageously, the maximum number of retries can prevent an excessive number of retries to avoid damage to the system 300 and / or reduce the wasted energy of "spinning up" the second electric traction motor 212 to attempt further retries.

[0236] Some embodiments of the present invention are configured to include an anti - fishing module (AFM) 540. The AFM 540 is configured to control a change in the coupling state of the second electric traction motor 212. In particular, the AFM 540 is configured to control the timing of a change in the coupling state of the second electric traction motor 212. The AFM 540 can ensure that a change in the coupling state of the second electric traction motor 212 does not occur too frequently, that is, at least a predetermined period is provided during a change in the coupling state of the second electric traction motor 212. The AFM 540 is illustrated in FIG. 4 as forming part of an arbiter 570. However, the AFM 540 may be arranged elsewhere, that is, other structures can be assumed.

[0237] FIG. 12 shows a method 1300 according to an embodiment of the present invention. The method 1300 is a method for controlling a change in the coupling state of the second electric traction motor 212 according to an embodiment of the present invention. The method 1300 may be executed by the AF module 540.

[0238] In step 1310 of the method, the coupling state of the second electric traction motor 212 to the second torque path via the second axle 222 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 depending on at least one attribute signal such as a speed signal 410 indicating the speed of the vehicle 100 or a driving mode signal 440. As described above, the coupling state of the second electric traction motor 212 may be determined by any of the modules 510, 520, 530, 550, 560, and corresponding signals or requests may be provided to the arbiter 570. For example, the HSM 510 may provide a request to disconnect the second electric traction motor 212 from the rear axle 222, while the FMM 530 may provide a request to couple the second electric traction motor 212 to the rear axle 222. Thus, requests for various coupling states may be originated from different modules. Advantageously, the AF module 540 is configured to prevent frequent changes in the coupling state of the second electric traction motor 212 in order to avoid such changes being noticed by the occupants of the vehicle 100. Step 1310 may consist of one or more requests for the coupling state being received by the arbiter 570, particularly the AFM 540.

[0239] Step 1320 includes determining whether a predetermined period has elapsed since the last or most recent previous change in the coupling state of the second electric traction motor 212. The predetermined period may be a period since the last request for a change in the coupling state was output by the controller 305 or since the success of the change in the coupling state reported by the coupling state signal 470. The predetermined period may be, for example, at least 5 seconds, at least 10 seconds, at least 20 seconds, or at least 30 seconds. It is understood that other periods may be assumed. If the predetermined period has elapsed, the method 1300 proceeds to step 1340.

[0240] If the specified period has not elapsed, the method proceeds to step 1330, and the AFM 540 is configured to wait, i.e., delay, by controlling the output means 340 of the controller 305 to output a coupling signal 345 indicating the required change in the coupling state until the specified period elapses from the last change in the coupling state. The AFM 540 may buffer incoming or received coupling state requests from the modules 510, 520, 530, 550, 560 until the expiration of the specified period, and the desired coupling state may be continuously re-evaluated during the specified period. Thus, at the expiration of the specified period, the coupling state can be determined based on the most recently received coupling state request rather than executing the first buffered request. Advantageously, this ensures that the coupling state requested at the expiration of the specified period reflects the latest attributes of the vehicle 100. When the specified period elapses, the method proceeds to step 1340.

[0241] In step 1340, the AF module 540 is configured to control the output means 340 of the controller 305 to output a coupling request signal 345 to control the coupling of the second electric traction motor 212 to the rear axle 222. In some embodiments, the inhibition module, as described, is provided with a signal 575 indicating the adjudicated coupling request.

[0242] Some embodiments of the present invention include an inhibition module 550. The inhibition module 550 is configured to control changes in the coupling state of the second electric traction motor 212. In particular, the inhibition module 550 is configured to enable inhibition of one or more coupling states of the second electric traction motor 212 with respect to the rear axle 222. Inhibition of the coupling state prevents the inhibited coupling state from being requested by the controller 305. The inhibition module 550 is shown in FIG. 4 as forming part of the arbiter 570. However, the inhibition module 550 may be configured elsewhere, i.e., other configurations are envisioned.

[0243] The disabling module 550 is configured to receive a disabling signal 460. The disabling signal indicates one or more coupling states of the second electric traction motor 212 to the rear axle 222 that are disabled or inhibited. The disabling signal 460 may indicate one of a coupled state and an uncoupled state of the second electric traction motor 212 with respect to the rear axle 222, and may also indicate one of a coupled state and an uncoupled state of the second electric traction motor 212 with respect to the rear axle 222. Although the disabling signal 460 is shown as one signal, it will be understood that in other embodiments, respective signals may be provided for each of the coupled state and the uncoupled state to indicate whether each state is disabled. The disabling module is configured to output a coupling state disabling signal 555 indicating a request for a coupled state to an arbiter, as described below. In particular, the coupling state disabling signal 555 indicates a request for a coupling state when its coupling state is not disabled, thereby further indicating which coupling state is not disabled.

[0244] FIG. 13 shows a method 1400 according to an embodiment of the present invention. The method 1400 is a method for controlling a change in the coupling state of the second electric traction machine 212 according to an embodiment of the present invention. The method 1400 may be executed by the disabling module 550.

[0245] In step 1410 of the method, the coupling state of the second electric traction motor 212 to the second torque path via the second axle 222 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 may be performed depending on a determination of the amount of power required to spin up the second electric traction motor 212 to the speed of the rear axle, compared to the amount of power available from the traction battery 200. As described above, the coupling state of the second electric traction motor 212 may be determined by any of the modules 510, 520, 530, 560, and a corresponding signal or request may be provided to the arbiter 570. For example, the HSM 510 may provide a request to disconnect the second electric traction motor 212 from the rear axle 222, while the FMM 530 may provide a request to couple the second electric traction motor 212 to the rear axle 222. Thus, requests for various coupling states may be originated from different modules. Advantageously, the inhibition module 550 is configured to prevent the coupling state of the second electric traction motor 212 from being selected, such as to avoid a state related to a failure. For example, if it is determined that there is a failure preventing the second electric traction motor 212 from coupling to the rear axle 222, the inhibition module 550 may be able to inhibit the coupling state to avoid the coupling state being selected. Similarly, in some embodiments, one or more coupling states may be inhibited depending on one or more of the power limitations or capabilities of the traction battery 200. For example, if the capability of the traction battery 200 is determined to provide sufficient power to spin up the second electric traction motor 212 for coupling to the rear axle 222, the coupling state may be prohibited in step 1410.

[0246] Step 1410 may include one or more requests for a coupling state being received by arbiter 570, particularly by inhibit module 550. As described below, arbiter 570 may determine a mediated coupling state depending on the received requests.

[0247] In step 1420, it is determined whether the determined coupling state is inhibited. The determined coupling state may be the arbitrated coupling state determined by arbiter 570. Step 1420 includes comparing the determined coupling state with one or more inhibited coupling states, such as when the coupling state is shown to be inhibited by inhibit signal 460. If the determined coupling state is different from the coupling state indicated by the inhibit signal, or if the coupling state is not shown to be inhibited, the method proceeds to step 1430. However, if the determined coupling state is shown to be prohibited by inhibit signal 460, the method returns to step 1410. In other words, method 1400 prevents a request for a prohibited coupling state from being output in step 1430.

[0248] In step 1430, inhibit module 550 is configured to control output means 340 of controller 305 to output a coupling request signal 345 for controlling the coupling of second electric traction motor 212 to rear axle 222. That is, when it is not shown that the determined coupling state is prohibited by inhibit signal 460, a request for the determined coupling state is output by controller 305.

[0249] Some embodiments of the present invention include a Drive Mode Module (DMM) 560. The DMM 560 is configured to determine the engagement state of the second electric traction motor 212 depending on the driving mode of the vehicle 100. The driving mode of the vehicle 100 is indicated by a drive mode signal 440. The driving mode of the vehicle 100 may be selected by the driver or passenger of the vehicle 100, or at least in part, for example, adaptively selected by a module or system of the vehicle 100 such as a Terrain Response (TR) module that selects a driving mode including one or more settings of its powertrain, such as the vehicle and in particular its traction control mode. The driving mode may include operating in a selected setting, including a driving mode of the vehicle that includes one of forward, reverse, or neutral in the case of an automatic transmission, such as a powertrain, or gear selection of a manual transmission. The driving mode may include a selection of one of a sports, normal, or economy driving mode in which one or more settings of the engine, first and / or second electric motors, suspension, etc. of the vehicle 100 can be adapted accordingly. Data indicating the selected driving mode(s) is provided by the drive mode signal.

[0250] FIG. 14 shows a method 1500 according to an embodiment of the present invention. The method 1300 is a method for controlling changes in the engagement state of the second electric traction motor 212 according to an embodiment of the present invention. Some of the steps of the method 1500 may be performed by the DMM 560.

[0251] In step 1510, a coupling state based on the attributes of the second electric traction motor 212 with respect to the second axle 222 is determined. The determination in step 1510 is performed depending on at least one attribute signal such as the speed signal 410 indicating the speed of the vehicle. As described above, the coupling state of the second electric traction motor 212 may be determined by any one of the modules 510, 520, 530, 560 and the corresponding signals or requests provided to the arbiter 570. For example, the HSM 510 may provide a request to disconnect the second electric traction motor 212 from the rear axle 222, while the FMM 530 may provide a request to couple the second electric traction motor 212 to the rear axle 222. Thus, requests for various coupling states may originate from different modules. Step 1510 may be performed by one or more of the HSM 510, LSM 520, and FMM 530. Step 1510 may be performed depending on the signals 515, 525, 535 excluding the driving mode signal 440. One or more signals indicating the determined coupling state are provided to the arbiter 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.

[0252] In step 1520, a drive-mode-based coupling state of the second electric traction motor 212 with respect to the second axle 222 is determined. Step 1520 is determined depending on the drive mode signal 440.

[0253] In one example, the drive mode signal 440 can indicate a selected drive mode of the vehicle, including a selection of a drive mode based on efficiency. The drive mode based on efficiency is selected to provide improved efficiency of the vehicle 100, i.e., reduced energy consumption, such as at the expense of the performance of the vehicle 100. The efficiency may be for improving the consumption of fuel supplied to the engine 202, or for saving the power consumed by the motors 212, 216. The drive mode signal 440 indicates a selection of a drive mode based on efficiency, which may be selected manually or automatically. Similarly, in another example, the drive mode signal may indicate that the neutral gear of the vehicle 100 is selected.

[0254] Depending on the drive mode signal 440, the DMM 560 is configured to determine a coupling state of the second electric traction motor 212 to the rear axle 222, e.g., one of coupled and uncoupled. A signal 565 indicating the coupling state based on the drive mode is provided to the arbiter 570. The coupling state based on the drive mode may be referred to as the second coupling state of the second electric traction motor 212. Thus, the coupling state determined in step 1520 may be uncoupled.

[0255] In another example, the drive mode signal 440 may indicate a drive mode (e.g., a drive mode that requires four-wheel drive of the vehicle 100) selected by the driver or automatically selected by a terrain response mode. The drive mode requires the connection of the second electric traction motor 212 to provide power to the rear axle 222. Thus, in step 1520, it may be determined that the coupling state is coupled.

[0256] In step 1530, it is determined whether the first and second coupling states are the same, i.e., equal. That is, whether the first coupling state as either coupled or uncoupled is equal to the second coupling state as either coupled or uncoupled. If the first and second coupling states are equal, the method proceeds to step 1540. However, if the first and second coupling states are different, the method proceeds to step 1550.

[0257] In step 1540, the output means 340 is controlled to output a coupling signal 345 indicating one of the first and second coupling states, i.e., either coupled or uncoupled.

[0258] In step 1550, when the determined first and second coupling states are different, the output means 340 is controlled to output a coupling signal 345 indicating the first coupling state, i.e., the coupling state based on the attribute. That is, the arbiter 570 is configured to assign a higher priority to the first coupling state than the second coupling state. This is reflected, as will be explained, by the efficiency column being furthest to the right in Table 1 below, such that the coupling state determined by, for example, the HSM 510, etc., is prioritized. Only when there is no request from other modules does the adjudicated coupling state follow the coupling state independently determined by the DMM 560.

[0259] FIG. 15 is a diagram showing the coupling state determined by the DMM560 according to some embodiments of the present invention. In some embodiments, the DMM560 depends on the drive mode signal 440 indicating one of drive (D), neutral (N), and reverse (R), such as the mode of the power train, particularly its gearbox, or gear selection, i.e., the shifter position, to determine the coupling state of the second electric traction motor 212. As can be understood, the DMM560 is configured not to require the coupling state 1630 when the power train is not in neutral, i.e., when one of D or R is selected, or when a gear of the gearbox is selected. In such a state, the DMM560 may output a no-requirement NR signal. However, as indicated by the driving mode signal 440, when N is selected 1620, the DMM560 is configured to output the coupling signal 565 to require the uncoupled state 1640. Therefore, the second electric traction motor 212 is required to be in an uncoupled state when N is selected.

[0260] As described above, some embodiments of the present invention constitute an arbiter 570. The arbiter 570 is configured to receive one or more requests for the coupling state of the second electric traction motor 212 and determine the overall or arbitrated coupling state of the second electric traction motor 212 with respect to the second axle 222. The arbiter 570 is configured to control the output means 340 of the controller 305 to output a coupling signal 345 indicating the same. The arbiter 570 is configured to assign a predetermined priority or precedence to at least some of the requests for the coupling state from different modules. Table 1 below identifies the requests for the coupling state received from various modules of the controller 305, the default coupling state, i.e., when there are no other requests, and the determined coupling state of the arbiter 570.

[0261]

Table 1

[0262] The arbiter 570 is configured to receive the FDCSR signal 535 from the FMM 530 by its input means. The arbiter 570 also receives a plurality of further coupling state request signals 515, 525, 565, namely from each of the modules 510, 520, 560. Each coupling state request signal indicates a request for the coupling state to at least one wheel of the second axle 222 of the second electric traction motor 212.

[0263] Refer to FIG. 10 showing a method for determining the coupling state in the presence of the FDCSR 535 from the FMM 530. The arbiter 570 is configured to determine the arbitration coupling state of the second electric traction motor 212 with respect to at least one wheel of the second axle 222 depending on the FDCSR signal 535 and at least one further coupling state request signal 515, 525, 565. The arbiter 570 is configured to determine the arbitration coupling state of the second electric traction motor 212 with priority given to the FDCSR signal 535 over at least one further coupling state request signal 515, 525, 565.

[0264] In FIG. 10, in step 1110, the arbiter 570 is configured to receive the FDCSR signal 535 from the FMM 530. The FDCSR signal 535 indicates a coupling state request as explained above. For example, the FDCSR signal 535 indicates a request for one of the coupled state or the uncoupled state as shown in Table 1.

[0265] In step 1120, the arbiter 570 is configured to receive any other coupling state request signal, namely signals from the modules 510, 520, 525, 565, 560. As contemplated by Table 1, it is understood that at some point no other coupling state requests are received simultaneously with the FDCSR 535.

[0266] In step 1130, the coupling state of the second electric traction motor 212 is determined depending on the FDCSR535 and other received coupling state requests. As can be understood from Table 1 above, when the FDCSR signal 535 indicates an uncoupled state (D), the arbiter 570 is configured to determine the mediated coupling state as uncoupled regardless of the states of the further coupling state request signals 515, 525, 565. Thus, the arbiter 570 is configured to determine the coupling state of the electric machine 212 with priority given to the FDCSR signal 535 over any further coupling state request signal. In particular, the arbiter 570 is configured to determine the uncoupled state of the second electric traction machine 212 with priority given to the FDCSR signal 535 indicating a request to uncouple the second electric traction machine 212 over any further coupling state request.

[0267] As can be understood from Table 1, when the arbiter 570 receives from the HSM510 a high-speed coupling state request 515, HSCSR, signal indicating a request (D) to disconnect the second electric traction motor 212 from the second axle 222, when the FDCSR535 is not received (NR), or when the FDCSR signal 535 indicates a coupling (C) request, the arbiter 570 determines to disconnect the adjudicated coupling state of the second electric traction motor 212 in response to the request from the HSM510, and advantageously protects the second electric traction motor 212 from excessive rotational speed. Thus, the decoupled request from the HSM510 is prioritized over the FDCSR535 when there is a conflict.

[0268] In step 1140, the arbiter 570 is configured to output an adjudicated coupling request signal 575 indicating the adjudicated coupling state in order to control the coupling of the second electric traction motor 212 to at least one wheel (RL, RR) of the second axle 222. The adjudicated coupling request signal 575 is output via the output means 340 of the controller 305 and controls the coupling of the second electric traction motor 212.

[0269] FIG. 16 is a diagram showing the overall operation of system 300. Trace 1701 represents a ruled coupling state request output by controller 305 as signal 345. Trace 1702 represents the actual coupling state of second electric traction motor 212 with respect to at least one wheel (RL, RR) of second axle 222. Trace 1703 is a connection prohibition signal, and trace 1704 is a disconnection or non-coupling state prohibition signal.

[0270] As can be understood, during period 1710, DMM 560 determines that the coupling state is non-coupled, such as based on the fact that the driving mode signal 440 indicates an efficiency-based driving mode. The coupling state in which being coupled is suppressed does not have an impact because, as shown by 1703, the ruled coupling state is non-coupled. During period 1720, DMM 560 determines that the coupling state is coupled based on the IDD driving mode indicated by the drive mode signal 440. However, the connection prohibition signal 1703 indicates that the coupling state is prohibited, whereby the actual coupling state is that the decoupling, i.e., the coupling prohibited state, takes precedence over the coupling state requested by DMM 560. However, during period 1730, once the coupling state inhibition signal 1703 indicates that it is not inhibiting the coupling state, the coupling state is realized. During period 1740, the coupling state is requested as the default coupling state of arbiter 570. Partially during period 1740, the non-coupling state is inhibited as shown by trace 1704, but this does not affect the coupling state during period 1740 because the coupling is still requested by arbiter 570. However, during period 1750 when the non-coupling state is requested by HSM 510, the coupling state is maintained because the non-coupling is still inhibited. When the inhibition is released during period 1760, a non-coupled coupling state is requested by arbiter 570 corresponding to the requested state of HSM 510. During period 1760, LSM 520 requests the coupling state.

[0271] Embodiments of the present invention can be realized in the form of hardware, software, or a combination of hardware and software. Any such software, whether erasable or rewritable, can be in the form of volatile or non-volatile storage, such as a storage device like ROM, or in the form of memory, such as RAM, memory chips, devices, or integrated circuits, or can be stored on optically or magnetically readable media, such as CDs, DVDs, magnetic disks, or magnetic tapes. It is understood that the storage devices and storage media are embodiments of machine-readable storage suitable for storing a program or programs that, when executed, implement the embodiments of the present invention. Thus, an embodiment provides a program that includes code for implementing the system or method described in any preceding claim, and a machine-readable storage for storing such a program. Further, embodiments of the present invention may be electronically transmitted via any medium, such as a communication signal carried via a wired or wireless connection, and embodiments preferably include this.

[0272] All features disclosed in this specification (including the appended claims, abstract and drawings), and / or all steps of any method or process so disclosed, may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. Each feature disclosed in this specification (including the appended claims, abstract and drawings) may be replaced by an alternative feature serving the same, equivalent or similar purpose, unless expressly stated otherwise. Accordingly, each feature disclosed is only an example of a general series of equivalent or similar features, unless expressly stated otherwise. The 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 the features disclosed in this specification (including the appended claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. The claims should not be construed as merely covering the foregoing embodiments, but should also be construed to cover any embodiment falling within the scope of the claims.

Claims

1. An electromechanical control system for a vehicle, wherein the electromechanical control system includes one or more controllers, the vehicle is provided with an electromechanical device configured to be selectively coupled to provide torque to at least one wheel of an axle of the vehicle, the control system includes, input means for receiving a speed signal (410) indicative of the speed of the vehicle, processing means configured to determine a desired coupling state of the electromechanical device to the at least one wheel of the axle depending on the speed signal, wherein the processing means determines the desired coupling state, depending on the speed signal indicating a vehicle speed equal to or higher than a first high-speed threshold, as a non-coupled state, depending on the speed signal indicating a vehicle speed equal to or lower than a second high-speed threshold, as a non-demand state, the non-demand state being a state indicating that no specific coupling state of the electromechanical device to at least one of the wheels of the axle is required, the second high-speed threshold indicating a vehicle speed lower than the first high-speed threshold, and processing means, output means configured to output a coupling signal indicating the coupling state to control the coupling of the electromechanical device to the at least one wheel of the axle. A control system comprising.

2. The control system according to claim 1, wherein the processing means is configured to determine the desired coupling state depending on the speed signal indicating a vehicle speed between the first high-speed threshold and the second high-speed threshold.

3. The input means is configured to receive a temperature signal, The control system according to claim 1 or 2, wherein the processing means is configured to determine the coupling state depending on the temperature signal.

4. The input means is configured to receive a charge signal indicative of the state of charge of one or more batteries for supplying power to the electromechanical device, The control system according to any one of claims 1 to 3, wherein the processing means is configured to determine the coupling state depending on the charge signal.

5. The control system according to claim 4, wherein the processing means is configured to determine the second high-speed threshold depending on the charge signal.

6. The control system according to claim 4, wherein the processing means is configured to determine the desired coupling state of the electromechanical device as uncoupled depending on the charging signal indicating that the state of charge of the one or more batteries is less than a predetermined threshold and the speed signal indicating a vehicle speed less than the second high speed threshold.

7. The input means is configured to receive one or more additional signals indicating the state of one or more further vehicle subsystems or one or more attributes of the vehicle, The control system according to any one of claims 1 to 6, wherein the processing means is configured to determine the desired coupling state of the electromechanical device at least partially depending on the one or more additional signals.

8. The control system according to claim 7, dependent on claim 2, wherein the processing means is configured to determine the desired coupling state of the electromechanical device giving priority to the speed signal over the one or more additional signals.

9. The first high speed threshold represents a vehicle speed less than a desired decoupling vehicle speed, The control system according to any one of claims 1 to 8, wherein when the vehicle is accelerating and the vehicle reaches the desired decoupling vehicle speed, the electromechanical device is decoupled from at least one of the wheels of the axle.

10. A powertrain comprising the control system according to any one of claims 1 to 9.

11. A vehicle comprising the control system according to any one of claims 1 to 9 or the powertrain according to claim 10.

12. A method of controlling the coupling of an electromechanical device to provide torque to at least one wheel of a vehicle axle, the method comprising: Receiving a speed signal indicating the speed of the vehicle; Determining, depending on the speed signal, a coupling state of the electromechanical device to the at least one wheel of the axle, wherein the coupling state is determined as an uncoupled state depending on the speed signal indicating a vehicle speed greater than or equal to a first high speed threshold, configured to be determined as a no-demand state depending on the speed signal indicating a vehicle speed less than or equal to a second high speed threshold, the no-demand state being a state indicating that no specific coupling state of the electromechanical device to at least one of the wheels of the axle is required, and the second high speed threshold indicating a vehicle speed lower than the first high speed threshold. A method comprising the step of outputting a coupling signal indicating the coupled state to control the coupling of the electromechanical device to the at least one wheel of the axle. **Claim 13** Computer software configured to execute the method according to claim 12 when executed by a computer, wherein the computer software is stored on a computer-readable medium.

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