METHODS AND SYSTEMS FOR VARIABLE DISPLACEMENT ENGINE CONTROL

摘要

Methods and systems are provided for selecting a group of cylinders for selective deactivation, in a variable displacement engine system, based at least on a regeneration state of an exhaust catalyst. The position of one or more valves and throttles may be adjusted based on the selective deactivation to reduce back-flow through the disabled cylinders while also maintaining conditions of a downstream exhaust catalyst. Pre-ignition and knock detection windows and thresholds may also be adjusted based on the deactivation to improve the efficiency of knock and pre-ignition detection.

主权项

1. A method of operating an engine with selectively deactivatable cylinders carried out by a processor communicating with the engine, comprising:
boosting air to the engine with twin turbochargers;
deactivating a determined number of cylinders; adjusting a crank angle window range and a threshold based on the number of deactivated cylinders; and indicating cylinder pre-ignition based on a sensed signal only in the crank angle window range relative to the threshold.