INTERNAL COMBUSTION ENGINE CONTROL FOR IMPROVED FUEL EFFICIENCY
First Claim
1. A method of controlling the operation of an internal combustion engine having a plurality of working chambers, each working chamber being generally arranged to operate in a succession of working cycles, the method comprising operating the engine in a variable displacement mode that includes:
- delivering air and fuel to the working chambers during selected active working cycles;
firing the working chambers in a firing pattern determined during operation of the engine that skips the firing of selected skipped working cycles and fires the active working cycles;
wherein the firing pattern is determined at least in part using predictive adaptive control to provide a desired engine output, and wherein the predictive adaptive control includes feedback indicative of at least one of requested and actual working cycle firings.
1 Assignment
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Accused Products
Abstract
A variety of methods and arrangements for improving the fuel efficiency of internal combustion engines are described. Generally, an engine is controlled to operate in a skip fire variable displacement mode. Feedback control is used to dynamically determine the working cycles to be skipped to provide a desired engine output. In some embodiments a substantially optimized amount of air and fuel is delivered to the working chambers during active working cycles so that the fired working chambers can operate at efficiencies close to their optimal efficiency. In some embodiments, the appropriate firing pattern is determined at least in part using predictive adaptive control. By way of example, sigma delta controllers work well for this purpose. In some implementations, the feedback includes feedback indicative of at least one of actual and requested working cycle firings. In some embodiments, the appropriate firings are determined on a firing opportunity by firing opportunity basis. Additionally, in some embodiments, an indicia of the current rotational speed of the engine is used as a clock input for a controller used to selectively cause the skipped working cycles to be skipped.
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Citations
20 Claims
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1. A method of controlling the operation of an internal combustion engine having a plurality of working chambers, each working chamber being generally arranged to operate in a succession of working cycles, the method comprising operating the engine in a variable displacement mode that includes:
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delivering air and fuel to the working chambers during selected active working cycles; firing the working chambers in a firing pattern determined during operation of the engine that skips the firing of selected skipped working cycles and fires the active working cycles; wherein the firing pattern is determined at least in part using predictive adaptive control to provide a desired engine output, and wherein the predictive adaptive control includes feedback indicative of at least one of requested and actual working cycle firings. - View Dependent Claims (2, 3, 4, 5, 6, 8)
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7. A method as recited in clam 1 wherein the predictive adaptive control is provided at least in part by a sigma delta controller.
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9. An engine controller for controlling the operation of an internal combustion engine having at least one working chamber, each working chamber being generally arranged to operate in a succession of working cycles, wherein the engine controller is arranged to:
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receive and input signal indicative of a desired engine output; determine a skip fire firing pattern that fires selected active working cycles and causes selected passive working cycles not to be fired to provide the desired engine output; and use predictive adaptive control that includes feedback indicative of at least one of requested and actual working cycle firings in the determination of the skip fire firing pattern. - View Dependent Claims (10, 11, 12, 13)
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14. An engine controller arranged to control working chamber firing in an engine, the engine controller comprising:
a sigma delta controller arranged to receive an input signal indicative of a desired engine output and to output a drive pulse signal indicative of working cycle firings that are appropriate to deliver the desired output, wherein the drive pulse signal is used at least in part to determine a firing pattern that fires selected active working cycles and skips firing selected passive working cycles. - View Dependent Claims (15, 16, 17, 18, 19, 20)
Specification