Control systems and methods for air fuel imbalance and cylinder deactivation
First Claim
1. An engine control system comprising:
- a torque request module that determines a torque request for an engine based on a driver input;
a cylinder control module that, based on the torque request, determines a target fraction of a number of cylinders of the engine to be activated out of a total number of cylinders of the engine;
an air fuel imbalance (AFIM) module that selectively commands that the cylinder control module set the target fraction to a predetermined fraction of the total number of cylinders of the engine to be activated,wherein the cylinder control module further;
sets the target fraction to the predetermined fraction in response to the command; and
activates and deactivates opening of intake and exhaust valves of the cylinders of the engine based on the target fraction; and
wherein the AFIM module further, while the target firing fraction is set to the predetermined fraction, selectively diagnoses the presence of an AFIM fault based on samples of a signal from an oxygen sensor measuring oxygen in exhaust upstream of a catalyst of an exhaust system.
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Accused Products
Abstract
A torque request module determines a torque request for an engine based on a driver input. A cylinder control module determines a target fraction of a total number of cylinders of the engine to be activated based on the torque request. An air fuel imbalance (AFIM) module selectively commands that the cylinder control module set the target fraction based on a predetermined fraction of the total number of cylinders of the engine to be activated. The cylinder control module further: sets the target fraction based on the predetermined fraction in response to the command; and activates and deactivates opening of intake and exhaust valves of the cylinders of the engine based on the target fraction. The AFIM module further, while the target firing fraction is set based on the predetermined fraction, selectively diagnoses the presence of an AFIM fault based on samples of a signal from an oxygen sensor.
48 Citations
19 Claims
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1. An engine control system comprising:
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a torque request module that determines a torque request for an engine based on a driver input; a cylinder control module that, based on the torque request, determines a target fraction of a number of cylinders of the engine to be activated out of a total number of cylinders of the engine; an air fuel imbalance (AFIM) module that selectively commands that the cylinder control module set the target fraction to a predetermined fraction of the total number of cylinders of the engine to be activated, wherein the cylinder control module further; sets the target fraction to the predetermined fraction in response to the command; and activates and deactivates opening of intake and exhaust valves of the cylinders of the engine based on the target fraction; and wherein the AFIM module further, while the target firing fraction is set to the predetermined fraction, selectively diagnoses the presence of an AFIM fault based on samples of a signal from an oxygen sensor measuring oxygen in exhaust upstream of a catalyst of an exhaust system. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An engine control system comprising:
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a torque request module that determines a torque request for an engine based on a driver input; a cylinder control module that; based on the torque request, determines a target fraction of a number of cylinders of the engine to be activated out of a total number of cylinders of the engine; and determines a target firing sequence for the cylinders to achieve the target fraction; an air fuel imbalance (AFIM) module that selectively commands that the cylinder control module set the target firing sequence to a predetermined firing sequence, wherein the cylinder control module further; sets the target firing sequence to the predetermined firing sequence in response to the command; and activates and deactivates opening of intake and exhaust valves of the cylinders of the engine in order according to the target firing sequence; and wherein the AFIM module further, while the target firing sequence is set to the predetermined firing sequence, selectively diagnoses the presence of an AFIM fault based on samples of a signal from an oxygen sensor measuring oxygen in exhaust upstream of a catalyst of an exhaust system. - View Dependent Claims (9, 10, 11, 12, 13)
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14. An engine control system comprising:
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a torque request module that determines a torque request for an engine based on a driver input; a cylinder control module that; based on the torque request, determines a target fraction of a number of cylinders of the engine to be activated out of a total number of cylinders of the engine; and activates and deactivates opening of intake and exhaust valves of the cylinders of the engine based on the target fraction; and an air fuel imbalance (AFIM) module that selectively diagnoses the presence of an AFIM fault based on samples of a signal from an oxygen sensor measuring oxygen in exhaust upstream of a catalyst of an exhaust system received when the target fraction is greater than a predetermined minimum fraction of the total number of cylinders of the engine. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification