Method for split ignition timing for idle speed control of an engine
First Claim
1. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:
- operating the first group of cylinders at a first ignition timing;
operating the second group of cylinders at a second ignition timing more retarded than said first group;
determining a signal based on a desired and actual speed; and
adjusting said first ignition timing based on said signal.
3 Assignments
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Accused Products
Abstract
A method is disclosed for controlling operation of an engine coupled to an exhaust treatment catalyst. Under predetermined conditions, such as after an engine cold start, the method operates an engine with a first group of cylinders having a first ignition timing, and a second group of cylinders having a second ignition timing more retarded than the first group. In addition, the engine control method also provides the following features in combination with the above-described split air/lean mode: idle speed control, sensor diagnostics, air/fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, default operation, and exhaust gas and emission control device temperature control. In addition, the engine control method also can change to combusting all cylinders at substantially the same ignition timing under preselected operating conditions such as fuel vapor purging, manifold vacuum control, and purging of stored oxidants in an emission control device.
68 Citations
27 Claims
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1. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:
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operating the first group of cylinders at a first ignition timing;
operating the second group of cylinders at a second ignition timing more retarded than said first group;
determining a signal based on a desired and actual speed; and
adjusting said first ignition timing based on said signal. - View Dependent Claims (2, 3, 4)
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5. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, the engine also having an electronically controlled throttle, comprising:
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operating the first group of cylinders at a first ignition timing;
operating the second group of cylinders at a second ignition timing more retarded than said first group;
determining a signal based on a desired and actual speed; and
adjusting the electronic throttle and said first ignition timing based on said signal. - View Dependent Claims (6, 7, 8, 9, 10)
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11. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:
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starting the engine; and
after starting the engine;
operating the first group of cylinders at a first ignition timing;
operating the second group of cylinders at a second ignition timing more retarded than said first group;
determining a signal based on a desired and actual speed; and
adjusting said at least one of said first and second ignition timing based on said signal. - View Dependent Claims (12, 13)
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14. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:
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starting the engine; and
indicating that the engine has been started based on at least one engine operating condition; and
in response to said indication;
operating the first group of cylinders at a first ignition timing;
operating the second group of cylinders at a second ignition timing more retarded than said first group;
determining a signal based on a desired and actual speed; and
adjusting said first ignition timing based on said signal.
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15. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:
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starting the engine; and
indicating that the engine has been started and catalyst light-off is desired based on at least one engine operating condition; and
in response to said indication;
operating the first group of cylinders at a first ignition timing;
operating the second group of cylinders at a second ignition timing more retarded than said first group;
determining a signal based on a desired and actual speed; and
adjusting said at least one of said first and second ignition timing based on said signal. - View Dependent Claims (16, 17)
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18. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:
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operating the first group of cylinders at a first ignition timing;
operating the second group of cylinders at a second ignition timing more retarded than said first group;
determining a signal based on a desired and actual speed; and
adjusting said first ignition timing based on said signal up to a predetermined value, and then advancing said second ignition timing based on said signal.
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19. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:
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operating the first group of cylinders at a first ignition timing;
operating the second group of cylinders at a second ignition timing more retarded than said first group;
determining a desired engine output;
adjusting at least one of said first and second ignition timing based on said signal; and
adjusting airflow through the engine based on said signal. - View Dependent Claims (20, 21)
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22. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:
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operating the first group of cylinders at a first ignition timing;
operating the second group of cylinders at a second ignition timing more retarded than said first group;
determining a signal based on a desired engine speed; and
adjusting at least one of said first and second ignition timing based on said signal. - View Dependent Claims (23, 24, 25)
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26. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:
indicating emission control device is less than a preselected value;
in response to said indication;
operating the first group of cylinders at a first ignition timing;
operating the second group of cylinders at a second ignition timing more retarded than said first group;
determining a signal based on a desired engine speed; and
adjusting at least one of said first and second ignition timing based on said signal. - View Dependent Claims (27)
Specification