Aspects of the present invention relate to a method and to a control system for a vehicle, the vehicle comprising an internal combustion engine configured to provide torque to a first axle of the vehicle for generating first axle wheel torque, and an electric machine configured to provide torque to a second axle of the vehicle for generating second axle wheel torque, the method comprising: outputting a torque request for the engine and a torque request for the electric machine, the torque requests having a first ratio dependent on a required torque split between the first axle wheel torque and the second axle wheel torque, wherein received first axle wheel torque and received second axle wheel torque have a second variable ratio dependent on a difference between wheel torque response capabilities of the engine and of the electric machine; determining that a trigger condition is satisfied; and controlling, in dependence on satisfaction of the trigger condition, determination of the torque request for the electric machine such that deviation of the second ratio from the first ratio is inhibited.

Embodiments of the present invention provide An electric machine control system for a vehicle, the electric machine control system comprising one or more controllers, wherein the vehicle comprises an electric machine arranged to be selectively coupleable to provide torque to at least one wheel of an axle of the vehicle, the control system comprising input means (330) to receive at least one attribute signal (410-4X0) indicative of one or more attributes of the vehicle (100), output means (340) arranged to output a coupling signal (345) to control coupling of the electric machine to the at least one wheel of the axle (222), and processing means (310) arranged to determine (1310) a coupling state of the electric machine (212) to the at least one wheel of the axle in dependence on the at least one attribute signal, wherein the processing means is arranged to control the output means to output the coupling signal (345) indicative of the determined coupling state, wherein the processing means is arranged to defer (1320, 1330) controlling the output means to output the coupling signal indicative of a change in the coupling state until expiry of a predetermined period of time since a last change in the coupling state indicated by the coupling signal.

Embodiments of the present invention provide An electric machine control system for a vehicle, the electric machine control system comprising one or more controllers, wherein the vehicle comprises an electric machine arranged to be selectively coupleable to provide torque to at least one wheel of an axle of the vehicle, the control system comprising input means to receive a speed signal indicative of a speed of the vehicle, processing means arranged to determine a coupling state of the electric machine to the at least one wheel of the axle in dependence on the speed signal, and output means arranged to output a coupling signal indicative of the coupling state to control coupling of the electric machine to the at least one wheel of the axle.

Aspects of the present invention relate to a method (400) and to a control system (208) for controlling at least one electric machine (212, 216) of a vehicle (10) to support diagnostic testing of a vehicle system (30) comprising an internal combustion engine (202), wherein the method (400) comprises: controlling a torque output (420) of the at least one electric machine (212,216) to allow a vehicle drive torque demand (410) to be met while the internal combustion engine (202) is operated within at least one torque threshold (432) for the diagnostic testing or operated at a torque setpoint (438) for the diagnostic testing.

Embodiments of the present invention provide an electric machine control system for a vehicle, the electric machine control system comprising one or more controllers, wherein the vehicle comprises an electric machine arranged to be selectively coupleable to provide torque to at least one wheel of an axle of the vehicle, the control system comprising input means to receive at least one attribute signal indicative of one or more attributes (410, 420, 430) of the vehicle and an efficiency signal (440) indicative of selection of an efficiency-based driving mode, output means arranged to output a coupling signal to control coupling of the electric machine to the at least one wheel of the axle, processing means arranged to determine (1510) a first coupling state of the electric machine to the at least one wheel of the axle in dependence on the at least one attribute signal and to determine (1520) a second coupling state of the electric machine to the at least one wheel of the axle in dependence on the at least one efficiency signal, wherein the processing means is arranged to control (1540) the output means to output the coupling signal indicative of the first and second coupling states when the same, and to output (1550) the coupling signal indicative of the first coupling state when the determined first and second coupling states differ.

Aspects of the present invention relate to a method and to a control system for a vehicle, the method comprising: receiving a torque request for an internal combustion engine configured to mechanically couple to a first axle of the vehicle; determining a shortfall relative to the torque request, dependent on torque providable by the engine; and providing an output to control an electric machine to provide a compensation torque configured to compensate for the shortfall, wherein the electric machine is mechanically coupled to a second axle of the vehicle.

Aspects of the present invention relate to a method and to a control system for a vehicle, the method comprising: determining that a trigger condition is satisfied, wherein satisfaction of the trigger condition is dependent on a vehicle speed of the vehicle relative to at least one threshold speed, the at least one threshold speed having a value corresponding to is vehicle speed no greater than four metres per second; and based at least on the determination, controlling when a mode change between a first operating mode and a second operating mode is performed, wherein in the first operating mode the internal combustion engine is in a disconnected state not configured to provide tractive torque, and an electric machine is configured to provide tractive torque, and wherein in the second operating mode at least the internal combustion engine is in a connected state configured to provide tractive torque.

Aspects of the present invention relate to a method and to a control system for a vehicle, the method comprising: determining that a trigger condition is satisfied, wherein satisfaction of the trigger condition is dependent on a vehicle speed of the vehicle relative to at least one threshold speed, the at least one threshold speed having a value corresponding to is vehicle speed no greater than four metres per second; and based at least on the determination, controlling when a mode change between a first operating mode and a second operating mode is performed, wherein in the first operating mode the internal combustion engine is in a disconnected state not configured to provide tractive torque, and an electric machine is configured to provide tractive torque, and wherein in the second operating mode at least the internal combustion engine is in a connected state configured to provide tractive torque.

Aspects of the present invention relate to a control system 208 and method for controlling energy management of a traction battery 200 of a hybrid electric vehicle 10, the traction battery 200 configured to power at least one traction motor 212 coupled to an electric-only axle 213 of the vehicle 10 to provide all-wheel drive, the control system 208 comprising one or more electronic controllers 300, the one or more electronic controllers 300 configured to: determine a change of terrain mode and/or type for the vehicle and/or determine an increase in loading of the vehicle 10; select an energy management control strategy for the traction battery 200 of the vehicle 10 in dependence on the determined change in terrain mode and/or type and/or the determined increase in loading of the vehicle 10, wherein the traction battery 200 is configured to supply power to the at least one traction motor 212 to provide torque to the electric-only axle 213 of the vehicle 10 to enable the vehicle 10 to operate in an all-wheel drive mode, wherein selecting an energy management control strategy of the vehicle 10 comprises at least one of: selecting or adjusting a charge sustain set point 30 for the traction battery 200; and changing energy generation to recharge the traction battery 200.

A drivetrain system for a vehicle is described, and includes an internal combustion engine, a geartrain, an electric machine, a power take-off unit, and a driveline. The internal combustion engine is coupled to the geartrain via a disconnect clutch and a torque converter. The geartrain includes a transmission and a differential gearset, including an output member of the transmission coupled to an input member of the differential gearset. The input member of the differential gearset is coupled to a rotor of the electric machine and the power take-off unit. The differential gearset is coupled to first and second intermediate driveshaft members of the driveline to transfer propulsion power to vehicle wheels that are arranged in a front-wheel configuration.