Apparatus and method for controlling an electric machine

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:

• an input to receive at least one attribute signal indicative of one or more attributes of the vehicle, wherein the at least one attribute signal comprises a speed signal indicative of a speed of the vehicle;
• an output arranged to output a coupling signal, wherein the output controls coupling of the electric machine to the at least one wheel of the axle based at least in part on the coupling signal;
• and
• a processor arranged to determine a coupling state of the electric machine to the at least one wheel of the axle in dependence on the at least one attribute signal, wherein the processor is arranged to control the output to output the coupling signal indicative of the determined coupling state, wherein the processor is arranged to defer controlling the output 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, wherein the last change in the coupling state comprises at least one of (i) a last request for a change in coupling state output by the one or more controllers, and (ii) a last successful change in coupling state,
• wherein, if the speed is greater than a speed threshold, the change in the coupling state is from coupled to decoupled,
• wherein the coupling signal is derived in determination of a fault associated with the vehicle, wherein a fault management module requests the coupling state of coupled or decoupled to control a state of the clutch to manage or resolve the fault associated with the vehicle.