Mode selection in a variable displacement engine

摘要

A system for selecting the operating mode of a variable displacement engine includes a vacuum analyser, a flow analyser, and a controller for determining whether the variable displacement engine should be operated on a fractional number of cylinders. The vacuum analyser generates a vacuum recommendation signal indicating whether a fractionally operating variable displacement engine can accommodate the inferred desired fractional manifold vacuum with respect to a desired torque and a specific emissions calibration. The flow analyser generates a flow recommendation signal indicating whether a fractionally operating variable displacement engine can accommodate a desired mass air flow and a desired exhaust gas recirculation flow with respect to a desired torque, a specific emissions calibration, and environmental conditions. The controller evaluates the vacuum and flow recommendation signals to determine the operating mode of the engine. <IMAGE>