An engine control unit (400) for a full hybrid engine (100, 101) is provided. The full hybrid engine (100, 101) comprises an internal combustion engine (110) and an electric motor (120). The internal combustion engine (110) is coupled to the drivetrain via a clutch (130). The engine control unit (400) is configured to operate the internal combustion engine (110) in a lean-burn mode, to determine a current load level of the full hybrid engine (100, 101), and to compare the current load level to a lean-burn load threshold (210). The lean-burn load threshold (210) defines a load level below which stable operation of the internal combustion engine (110) in the lean-burn mode is impossible and/or undesirable. If the current load level of the full hybrid engine (100, 101) is below the lean-burn load threshold (210), the internal combustion engine (110) is decoupled from the drivetrain and the full hybrid engine (100, 101) is operated in an electric mode.

A hybrid transmission (18) for a motor vehicle drive train (12) of a motor vehicle (10) includes: a first transmission input shaft (24) for operatively connecting the hybrid transmission to an internal combustion engine (16); a second transmission input shaft (26) for operatively connecting the hybrid transmission to a first electric prime mover (14); an output shaft (28) for operatively connecting the hybrid transmission to a drive output (32); a planetary gear set (RS) connected to the second transmission input shaft and to the output shaft; spur gear pairs (ST1, ST2, ST3) arranged in multiple gear set planes for forming gear steps; and a plurality of gear change devices with shift elements (A, B, C, D, E, F) for engaging gear steps. The output shaft is of a countershaft design, and the planetary gear set is interlockable when decoupled from the first transmission input shaft.

The power controller, when switching from the second power-source drive to the first power-source drive, determines a specified power of the second power-source based on a ratio of the target transmission capacity of a clutch to the target vehicle power, and controls the second power-source based on the specified power.

A vehicle control system includes: multiple control units which controls operation of a vehicle including an internal combustion engine, a first electric motor connected to the internal combustion engine, and a second electric motor; and a network connected to the control units such that the control units perform communi cati on with each other. The control units include a first control unit which controls the internal combustion engine, a second control unit which controls the first motor, and a third control unit which controls the second motor, and each detect abnormality in communication via the network among the control units. Upon detection of abnormality in communication between the second control unit and the other control units via the network, the first control unit stops operation of the internal combustion engine, and the third control unit performs control such that the second motor outputs power for the vehicle to travel.

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.

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.

The present invention relates to a control system for compensating for variable inertia in a vehicle powertrain, the method comprising: determining (404) whether a torque source (202) is coupled to a wheel (FL, FR), and applying (408, 410) a torque change in dependence on angular acceleration associated with the torque source (202), in dependence on whether the torque source is coupled to the wheel. The present invention further relates to a corresponding method, vehicle, system and computer software.