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 the active working cycles;
firing the working chambers in a firing pattern dynamically determined on a firing opportunity by firing opportunity basis during operation of the engine that skips the firing of selected skipped working cycles and fires selected active working cycles;
wherein an amount of air and fuel delivered to the working chambers during a first set of the active working cycles is substantially optimized; and
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, selected combustion events are skipped during operation of the internal combustion engine so that other working cycles can operate at a better thermodynamic efficiency. In one aspect of the invention, an engine is controlled to operate in a variable displacement mode. In the variable displacement mode, fuel is not delivered to the working chambers (e.g. cylinders) during selected “skipped” working cycles. During active (“non-skipped”) working cycles, a maximum (e.g., unthrottled) amount of air and an optimized amount of fuel is delivered to the relevant working chambers so that the fired working chambers can operate at efficiencies closer to their optimal efficiency. A controller is used to dynamically determine the chamber firings required to provide the engine torque based on the engine'"'"'s current operational state and conditions. The chamber firings may be sequenced in real time or in near real time in a manner that helps reduce undesirable vibrations of the engine.
171 Citations
50 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 the active working cycles; firing the working chambers in a firing pattern dynamically determined on a firing opportunity by firing opportunity basis during operation of the engine that skips the firing of selected skipped working cycles and fires selected active working cycles; wherein an amount of air and fuel delivered to the working chambers during a first set of the active working cycles is substantially optimized; and 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)
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6. An internal combustion engine comprising:
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a plurality of working chambers each arranged to operate in a succession of working cycles; a fuel delivery system arranged to facilitate the delivery of fuel into the working chambers; and a firing control unit arranged to control working chamber firings in the engine, wherein the firing control unit has a variable displacement operational mode that causes selected active working cycles to be fired and selected passive working cycles not to be fired, the firing control unit including, a drive pulse generator arranged to receive an input indicative of a desired engine output and to output a drive pulse signal that is synchronized with the engine speed, wherein the drive pulse signal defines a drive pulse pattern that generally indicates when active working cycles are appropriate to deliver the desired engine output; and a sequencer that receives the drive pulse signal and determines the active and passive working cycles based at least in part on the received drive pulse signal. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 47)
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7. (canceled)
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15-16. -16. (canceled)
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17. 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, wherein the method comprises operating the engine in a skip fire continuously variable displacement mode that includes:
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generating a drive pulse pattern that is synchronized with firing opportunities of the engine, wherein the drive pulse pattern generally indicates when working cycles need to be fired to deliver a desired engine output; generating a firing pattern based at least in part on the drive pulse pattern, wherein the firing pattern is not always the same as the drive pulse pattern; and firing the at least one working chamber in accordance with the firing pattern, wherein the firing pattern skips the firing of selected skipped working cycles and fires selected active working cycles. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. An engine controller arranged to control working chamber firings in an engine, wherein the engine controller has a variable displacement operational mode that causes selected active working cycles to be fired and selected passive working cycles not to be fired, the engine controller comprising:
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a drive pulse generator arranged to receive an input indicative of a desired engine output and to output a drive pulse signal that is synchronized with the engine speed, wherein the drive pulse signal defines a drive pulse pattern that generally indicates when active working cycles are appropriate to deliver the desired engine output; and a sequencer that receives the drive pulse signal and determines the active and passive working cycles based at least in part on the received drive pulse signal. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46)
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48. A method of controlling the operation of an internal combustion engine having a plurality of working chambers in a variable displacement mode, each working chamber being generally arranged to operate in a sequence of working cycles, the method comprising:
causing selected working cycles to be skipped while insuring that all of the working chambers are fired in a fixed sequential order such that no working chamber will fire twice in the variable displacement mode before each of the other working chambers has been fired, wherein the selection of the skipped working cycles is determined to deliver a desired output.
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49. A method of controlling the operation of an internal combustion engine having at least one cylinder, each cylinder having an associated reciprocating piston positioned therein, wherein each cylinder has a working cycle defined by a set integer number of sequential reciprocations of the associated piston, the working cycle including an expansion stroke that involves burning fuel, the method comprising:
operating the engine in a variable displacement mode in which a number of reciprocations of a selected piston that is not an integer multiple of the set number of sequential reciprocations that define a working cycle sometimes occur between the end of a first working cycle and a beginning of a next sequential working cycle that includes an expansion stroke that involves burning fuel.
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50. A drive pulse generator suitable for use in an engine controller arranged to control working chamber firings in an engine, wherein the engine controller has a variable displacement operational mode that causes selected active working cycles to be fired and selected passive working cycles not to be fired, the drive pulse generator comprising:
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an input signal digitizer arranged to receive an analog input signal indicative of a desired engine output and to output a digitizer output signal that is a feedback modified digital representation of the analog input signal; and a synchronizer arranged to receive the digitizer output signal and to output a drive pulse signal that is synchronized with the engine speed, wherein the drive pulse signal generally indicates when active working cycles are appropriate to deliver the desired engine output; and wherein feedback indicative of at least one of the drive pulse signal or a firing pattern that is based at least in part on the drive pulse signal is fed back to the input signal digitizer and is used in the generation of the digitizer output signal.
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Specification