INTERNAL COMBUSTION ENGINE CONTROL FOR IMPROVED FUEL EFFICIENCY
First Claim
1. A method of 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, the method comprising operating the engine in a variable displacement mode that includes:
- firing the at least one working chamber in a firing pattern that skips selected skipped working cycles and fires selected active working cycles;
delivering a substantially optimized amount of air and fuel to the at least one working chamber during a first set of the active working cycles; and
wherein the firing pattern is determined at least in part using feedback control to provide a desired engine output.
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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.
159 Citations
23 Claims
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1. A method of 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, the method comprising operating the engine in a variable displacement mode that includes:
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firing the at least one working chamber in a firing pattern that skips selected skipped working cycles and fires selected active working cycles; delivering a substantially optimized amount of air and fuel to the at least one working chamber during a first set of the active working cycles; and wherein the firing pattern is determined at least in part using feedback control to provide a desired engine output. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. An engine controller suitable for use with an internal combustion engine having at least one working chamber, each working chamber being arranged to operate in a succession of working cycles, wherein the engine controller has a skip fire variable displacement operational mode arranged to direct selective firing of the at least one working chamber in a firing pattern that causes selected active working cycles to be fired and selected passive working cycles not to be fired, wherein the engine controller is further arranged to:
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direct the delivery of a substantially optimized amount of air and fuel to the at least one working chamber during a first set of the active working cycles; and dynamically calculate the firing pattern based at least in part on feedback control to deliver a desired power output. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
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Specification