System and method for controlling a hybrid powertrain

A system for controlling a hybrid powertrain having an electric motor, an engine and a transmission, the system comprising:

• an engine control module that (i) receives a torque request, and (ii) when the hybrid powertrain is being powered by the electric motor, determines whether to switch from the electric motor to the engine based on the torque request;
• and
• a transmission control module that, in response to a determination to switch from the electric motor to the engine,
• determines a target engine speed based on the torque request,
• switches the hybrid powertrain from the electric motor to the engine based on a comparison between a current engine speed and the target engine speed,
• determines a time duration during which the engine speed is to be changed,
• segregates the time duration into a plurality of time intervals, and
• separately determines respective intermediate target engine speeds to be achieved during each time interval,
• wherein the engine control module (i) receives each of the intermediate target speeds and (ii) sequentially increases the current engine speed to each of the intermediate target speeds during respective ones of the plurality of time intervals.