The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 16, 2004
Filed:
Oct. 24, 2002
Jing Sun, Bloomfield, MI (US);
Ilya V. Kolmanovsky, Ypsilanti, MI (US);
Ford Global Technologies, LLC, Dearborn, MI (US);
Abstract
A method and system for controlling internal combustion engine, such engine being adapted to operate in a selected one of a plurality of operating mode. One of such modes is characterized by stratified combustion and another one of such modes is characterized by a homogeneous combustion. The method and system includes determining from operating conditions of the engine and a demanded torque, a preferred one of the operating modes. Determining from such demanded torque whether operation such preferred operating mode is feasible. The method and system effects a transition of the engine to the preferred mode if such preferred mode is determined to be feasible; otherwise, such engine is operated in one of the modes which provides the minimum difference between the torque produced in such one of the modes and the demanded torque. The feasibility determining comprises determining maximum torque, &tgr; , producible by such engine in the stratified operating mode and determining minimum torque, &tgr; , producible by such engine in the homogeneous operating mode. The stratified mode is determined feasible if the demanded torque is less than the determined maximum torque, &tgr; , and the homogeneous mode is determined feasible if the demanded torque is greater than or equal to the determined minimum torque, &tgr; . Maximum torque, &tgr; , is determined as a function of engine operating speed, air charge and burned gas fraction in a cylinder of such engine and a lower limit of the air fuel ratio for stratified operation of such engine. Minimum torque, &tgr; , is determined as a function of engine operating speed, air charge in a cylinder of such engine, an upper limit of the air fuel ratio for homogeneous operation of such engine, burned gas fraction in the cylinder, and maximum delayed ignition timing from Maximum Brake Torque spark timing Spark timing is changed to meet demanded torque when operating in the homogeneous mode, and changing fuel flow to such cylinder when operating in the stratified mode.