Control system for a model-based knock suppression system using a multiple actuation strategy

摘要

The present invention provides for predicting peak cylinder temperatures above which knock in an engine may become more frequent and then provides one or more actuation approaches to reduce the knock of the engine while maintaining engine performance. The actuation approaches of the present invention include one or more of direct injection, engine gas recirculation, and spark retarding, where the application of one or more the actuation approaches is determined based upon using operational and engine characteristic inputs as well as modeling and estimation values as inputs in a feedforward control methodology.

主权项

1. A method for knock suppression within an engine comprising:
determining a plurality of input conditions of the engine; determining a plurality of modeling values associated with additional inputs in relation to the operation of the engine in a preferred state; determining an estimate temperature threshold for knock and one or more peak end gas temperature estimates based on the plurality of input conditions; determining a first actuation event by comparing a desired EGR fraction value with predetermined fraction system limits; selectively executing the first actuation event in response to a first command, wherein the first actuation event is not executed when the one or more peak end gas temperature estimates is less than the estimated temperature threshold for knock, and wherein the first actuation event is executed when the one or more peak end gas temperature estimates is greater than or equal to the estimated temperature threshold for knock; determining a second actuation event by comparing the one or more peak end gas temperature estimates with predetermined end gas temperature system limits; executing the second actuation event in response to a second command; determining a third actuation event after receiving feedback of a sensed knock value from a sensor determining sensed knock; and executing the third actuation event in response to a final command; wherein the first actuation event is an EGR event, the second actuation event is a direct injection event, and the third actuation event is a spark retarding event.