Patent ID: 8601813

Claim:
A method of controlling exhaust gas recirculation (EGR) in a turbocharged engine system including a high pressure (HP) EGR path and a low pressure (LP) EGR path, the method comprising: determining a target total EGR fraction for compliance with exhaust emissions criteria; and using a control subsystem having one or more controllers in communication with one or more sensors constructed and arranged to determine a target HP/LP EGR ratio to optimize other engine system criteria within constraints of the determined target total EGR fraction, and including: using at least engine speed and load as an input to a base model to output a base EGR value; using at least one other engine system parameter as an input to at least one adjustment model to output at least one EGR adjustment value; adjusting the base EGR value with the at least one EGR adjustment value to generate an adjusted EGR value; and using the adjusted EGR value to construe controllable engine components to optimize other engine system criteria while ensuring that emissions criteria are met.