Hybrid electric vehicle controller and method of controlling a hybrid electric vehicle

A method of controlling a hybrid electric vehicle, the method comprising:

• determining a required torque split between each of a first actuator and a second actuator in dependence on a first set of one or more vehicle parameters, the required torque split being an amount of torque required to be provided to a driveline of the vehicle by each actuator, wherein the first actuator comprises an engine and the second actuator comprises an electric machine, and
• providing an actuator request control output to control each actuator to provide an amount of torque according to the required torque split,
• the method further comprising overriding a required torque split output in dependence on a value of a second set of one or more vehicle parameters, and, in a first mode, controlling a speed of rotation of the first actuator to substantially match a speed of rotation of the second actuator prior to connecting the first actuator to the driveline, and, in a second mode, controlling a speed of rotation of the first actuator to vary with a speed of the vehicle when the first actuator is running and disconnected from the driveline of the vehicle such that a sound generated by the first actuator varies according to vehicle speed and creates a perception that the first actuator is connected to the driveline and driving the vehicle.

A controller for controlling a parallel-type hybrid electric vehicle, the controller being operable to control an engine and an electric machine to deliver motive torque to a driveline of the vehicle,

• wherein, in a first control mode, the controller controls the engine and the electric machine to drive the vehicle, wherein the controller controls a speed of rotation of the engine to substantially match a speed of rotation of the electric machine prior to connecting the engine to the driveline, and
• wherein, in a second control mode, the controller controls the electric machine to drive the vehicle and controls the engine to be disconnected from the driveline of the vehicle,
• the controller being operable, when in the second control mode, to control a speed of rotation of the engine to vary with a speed of the vehicle when the engine is running and disconnected from the driveline of the vehicle such that a sound generated by the engine varies according to the vehicle speed and creates a perception that the engine is connected to the driveline and driving the vehicle.