Hybrid powertrain control

A method of controlling a hybrid powertrain to deliver a requested powertrain output, the method comprising alternatingly:

• operating an engine in a first effective displacement mode that delivers less torque to the powertrain than the requested powertrain output and controllably utilizing energy drawn from an energy storage device to add torque to the powertrain to cause the net delivery of the requested powertrain output;
• and
• operating the engine in a second effective displacement mode that has a different displacement than the first effective displacement mode and that delivers more than the requested powertrain output and controllably subtracting torque from the powertrain to cause the delivery of the requested powertrain output, wherein excess energy subtracted from the powertrain is stored in the energy storage device, and
• whereby the engine alternatingly transition back and forth between the first and second effective displacement modes such that the engine alternatingly supplies less torque and more torque than the requested powertrain output.

An arrangement comprising:

• an engine capable of applying torque to a powertrain, wherein the engine is arranged to operate in at least one of a variable displacement mode and a skip fire mode;
• an electric motor/generator unit arranged to add torque to and subtract torque from the powertrain during operation of the engine in the variable displacement mode or the skip fire mode;
• a battery arranged to store electrical energy, the battery being coupled to the electric motor/generator unit such that the battery may be charged and discharged by the motor/generator unit;
• a capacitor arranged to store electrical energy, the capacitor being arranged in a manner that facilitates the storage of electrical energy generated by the motor/generator unit and the delivery of electrical energy to the motor/generator unit during operation of the engine in the variable displacement or the skip fire mode to facilitate adding torque to and subtracting torque from the powertrain;
• and
• a controller arranged to direct the engine and motor/generator unit to cooperatively deliver a requested output.

A hybrid powertrain controller suitable for use in a vehicle having an engine that drives a powertrain, at least one motor/generator unit arranged to add torque to and subtract torque from the powertrain and a capacitor arranged to store electrical energy, the hybrid powertrain controller comprising:

• an engine controller arranged to operate an engine in a manner that delivers a plurality of different effective displacements;
• a motor controller arranged to direct the operation of at least one motor/generator unit;
• and
• wherein the engine controller and motor controller are arranged to operate the engine and the motor/generator unit in a manner that delivers a requested powertrain output;
• and
• the engine controller and motor controller are further arranged to be capable of causing the engine to alternatingly (i) operate the engine in a first effective displacement mode that delivers less torque to the powertrain than the requested powertrain output while operating the motor/generator unit as a motor to add torque to the powertrain using energy stored in the capacitor to cause the net delivery of the requested powertrain output, and (ii) operate the engine in a second effective displacement mode that has a different displacement than the first effective displacement mode and that delivers more than the requested powertrain output while operating the motor/generator unit as a generator to subtract torque from the powertrain to cause the net delivery of the requested powertrain output, wherein electricity generated by the generator is used to charge the capacitor during operation of the engine in the second effective displacement mode.