阅读说明：本技术 用于车辆的双点火源的设备和系统 (Apparatus and system for dual ignition sources for a vehicle ) 是由 D·J·奥康诺尔 R·J·布雷默 J·S·科尔豪斯 于 2017-12-20 设计创作，主要内容包括：用于点燃内燃机的燃料的设备、方法和系统,一种点火系统包括与气缸的预燃烧室相关联的第一点火装置和与所述气缸的主燃烧室相关联的第二点火装置。发动机控制单元可操作地连接到所述发动机和所述点火系统两者,以独立于利用所述第二点火装置点燃燃料而利用所述第一点火装置点燃所述气缸的燃料。所述发动机控制单元确定燃烧状况的发生并且响应于所述燃烧状况的所述发生：(i)利用所述第一点火装置和所述第二点火装置两者点燃用于燃烧的燃料；或者(ii)仅利用所述第二点火装置点燃用于燃烧的燃料。所述发动机控制单元确定第二燃烧状况并且响应于所述第二燃烧状况,仅利用所述第一点火装置点燃燃料。(An ignition system includes a first ignition device associated with a pre-combustion chamber of a cylinder and a second ignition device associated with a main combustion chamber of the cylinder. An engine control unit is operatively connected to both the engine and the ignition system to ignite fuel for the cylinder with the first ignition device independently of igniting fuel with the second ignition device. The engine control unit determines an occurrence of a combustion condition and, in response to the occurrence of the combustion condition: (i) igniting fuel for combustion with both the first ignition device and the second ignition device; or (ii) igniting the fuel for combustion using only the second ignition device. The engine control unit determines a second combustion condition and ignites fuel using only the first ignition device in response to the second combustion condition.)

1. A method, comprising:

determining a first combustion condition of the internal combustion engine, comprising: an ignition system comprising a first ignition device for igniting fuel in a pre-combustion chamber of a cylinder and a second ignition device for igniting fuel in a main combustion chamber of the cylinder; and an engine control unit configured to initiate ignition with the first ignition device independently of the second ignition device; and

in response to the first combustion condition: (i) igniting fuel with the first ignition device and the second ignition device; or (ii) igniting fuel with the second ignition device to operate the engine without igniting fuel with the first ignition device.

2. The method of claim 1, further comprising:

determining an occurrence of a second combustion condition associated with operation of the internal combustion engine; and

operating the engine with only the first ignition device igniting fuel in response to the second combustion condition.

3. The method of claim 2, wherein the first combustion condition comprises at least one of: an engine cold start event, an ignition failure event, a misfire event, a knock event, an under-burned mixture event, and a low engine load event.

4. The method of claim 3, wherein the first combustion condition comprises an engine cold start event, wherein the cold start event is determined in response to one or more of: the engine coolant temperature is less than an engine coolant temperature threshold; the engine oil temperature is less than the engine oil temperature threshold; the engine speed is less than the engine speed threshold; the internal combustion engine is in a non-operating condition; and the cranking condition of the internal combustion engine indicates that the crankshaft rotation speed is less than the threshold rotation speed.

5. The method of claim 4, wherein the second combustion condition comprises one or more of: the engine coolant temperature is greater than the engine coolant temperature threshold; the engine oil temperature is greater than the engine oil temperature threshold; the engine speed is greater than the engine speed threshold; the internal combustion engine is in an operating condition; and the cranking condition indicates that the crankshaft speed is greater than the threshold speed.

6. The method of claim 3, wherein the first combustion condition is the ignition-failure event, and the ignition-failure event includes the first ignition failing to ignite the fuel in the pre-combustion chamber.

7. The method of claim 3, wherein the first combustion condition is the misfire event.

8. The method of claim 3, wherein the first combustion condition is the under-burned mixture event, and the under-burned mixture event is a lean-burned mixture event determined in response to at least one of an air-fuel ratio of a combustion mixture, a lambda sensor output, and an engine-out NOx sensor output.

9. The method of claim 7, further comprising disabling the ignition system for one combustion cycle associated with the cylinder upon detection of the misfire event; and

after the one combustion cycle is complete, reactivating the ignition system to ignite fuel with both the first ignition device and the second ignition device to operate the engine.

10. The method of claim 1, further comprising:

determining an ionization condition in the main combustion chamber with the second ignition device.

11. The method of claim 1, wherein the first ignition device and the second ignition device comprise one of a spark plug, a diesel pilot ignition device, a plasma ignition device, a laser ignition device, a thermal ignition device, or a non-thermal ignition device.

12. A system, comprising:

an internal combustion engine;

an ignition system comprising a first ignition device associated with a pre-combustion chamber of a cylinder and a second ignition device associated with a main combustion chamber of the cylinder;

an engine control unit operatively connected to both the internal combustion engine and the ignition system, the engine control unit configured to ignite fuel of the cylinder with the first ignition device independently of igniting fuel with the second ignition device;

wherein the engine control unit is configured to determine an occurrence of at least one combustion condition associated with an operating condition of the engine, the engine control unit further configured to, in response to the occurrence of the at least one combustion condition: (i) igniting fuel for combustion with both the first ignition device and the second ignition device; or (ii) operating the engine using only the second ignition device to ignite fuel for combustion.

13. The system of claim 12, further comprising:

wherein the engine control unit is configured to determine an occurrence of at least one second combustion condition associated with operation of the engine; and is

Wherein the engine control unit is further configured to operate the engine using only the first ignition device to ignite fuel in response to the second combustion condition.

14. The system of claim 12, wherein the at least one combustion condition comprises one or more of: an engine cold start event, an ignition failure event, a misfire event, a knock event, an under-burned mixture event, and an engine load event.

15. The system of claim 14, wherein the at least one combustion condition is the engine cold start event, and the engine cold start event is determined in response to one or more of: the engine coolant temperature is less than an engine coolant temperature threshold; the engine oil temperature is less than the engine oil temperature threshold; the engine speed is less than the engine speed threshold; the internal combustion engine is in a non-operating condition; and the cranking condition indicates that the crankshaft speed is less than the threshold speed.

16. The system of claim 12, wherein the second combustion condition comprises one or more of: the engine coolant temperature is greater than the engine coolant temperature threshold; the engine oil temperature is greater than the engine oil temperature threshold; the engine speed is greater than the engine speed threshold; the internal combustion engine is in an operating condition; and the cranking condition indicates that the crankshaft speed is greater than the threshold speed.

17. The system of claim 14, wherein the first combustion condition is the ignition-failure event, and the ignition-failure event is the first ignition failing to ignite the fuel in the pre-combustion chamber.

18. The system of claim 14, wherein the first combustion event is the misfire event, and the engine control unit is configured to detect the misfire event and disable the ignition system in one combustion cycle associated with the cylinder; and is

After completion of the one combustion cycle, the engine control unit is configured to reactivate the ignition system to ignite fuel with both the first ignition device and the second ignition device to operate the engine.

19. The system of claim 14, wherein the first combustion event is the under-burned mixture event, and the under-burned mixture event is a lean-burned mixture event determined in response to at least one of an air-fuel ratio, a lambda sensor output, and a NOx sensor output.

20. The system of claim 14, wherein the engine control unit is configured to disable the ignition system in response to the misfire event, and the engine control unit is configured to enable the ignition system to ignite fuel with both the first ignition device and the second ignition device in response to determining that the misfire event has ended.

21. The system of claim 14, wherein the engine load event comprises engine load less than an engine load threshold, intake manifold pressure less than an intake manifold pressure threshold, and cylinder pressure less than a cylinder pressure threshold.

22. The system of claim 12, wherein the second ignition device is further configured to sense an ionization condition in the combustion chamber.

23. The system of claim 12, wherein the first ignition device and the second ignition device comprise one of a spark plug, a diesel pilot ignition device, a plasma ignition device, a laser ignition device, a thermal ignition device, or a non-thermal ignition device.

Background

The present disclosure relates generally to ignition of internal combustion engines and more particularly, but not exclusively, to control of dual ignition sources under certain conditions.

Pre-combustion chamber arrangements in internal combustion engines reduce engine emissions and may improve performance. However, there are many conditions that may impede the operation of an internal combustion engine. One such condition includes unreliable fuel ignition in the pre-combustion chamber. Unreliable fuel ignition may occur for a number of reasons, such as engine cold start, engine knock, and too lean of a fuel combustion mixture. Thus, there remains an unmet significant need for the unique devices, methods, systems, and techniques disclosed herein.

Disclosure of Invention

Unique apparatus, methods, and systems are disclosed for igniting fuel in response to the occurrence of a first combustion condition or a second combustion condition. The system comprises: an internal combustion engine; an ignition system comprising a first ignition device associated with a pre-combustion chamber of a cylinder and a second ignition device associated with a main combustion chamber of the cylinder; and an engine control unit operatively connected to both the engine and the ignition system, wherein the engine control unit may ignite the fuel of the cylinder with the first ignition device independently of igniting the fuel with the second ignition device. The engine control unit determines an occurrence of a first combustion condition and, in response to the occurrence of the first combustion condition: (i) igniting the fuel for combustion with both the first ignition device and the second ignition device; or (ii) igniting the fuel for combustion using only the second ignition device. The engine control unit determines a second combustion condition and ignites the fuel using only the first ignition device in response to the second combustion condition.

This summary is provided to introduce a selection of concepts that are further described below in the illustrative embodiments. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

Drawings

The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:

FIG. 1 is a schematic diagram of a vehicle system.

FIG. 2 is a block diagram of a process for igniting fuel using the first ignition device and/or the second ignition device of the vehicle system of FIG. 1.

FIG. 3 is a table including a plurality of first combustion conditions.

FIG. 4 is a table including a plurality of cold start event conditions for a first combustion condition.

FIG. 5 is a table including a plurality of second combustion conditions.

Detailed Description

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated embodiments, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring to FIG. 1, a schematic diagram of a vehicle system 100 is shown. As shown, the vehicle system 100 includes an engine 102, an engine control unit 104, and an ignition system 106. The ignition system 106 includes a first ignition device 120 for igniting fuel in a pre-combustion chamber 122 of a cylinder 124. The ignition system 106 also includes a second ignition device 126 for igniting fuel in a main combustion chamber 128 of the cylinder 124. It should be understood that the illustrated configuration and components of the vehicle system 100 are merely one example, and that the present disclosure contemplates that a variety of different vehicle systems 100 and associated components may be utilized.

Various engines may be used, such as an internal combustion engine for engine 102. Operation of the engine 102 may result in operation of the ignition system 106. The engine control unit 104 (which may be configured to control various operational aspects of the vehicle system 100) may be implemented in a variety of ways. The engine control unit 104 may execute operating logic that defines various control, management, and/or regulation functions. The operating logic may be in the form of one or more microcontroller or microprocessor routines stored in non-transitory memory, dedicated hardware (such as a hardwired state machine), an analog computing machine, various types of programmed instructions, and/or other forms as will occur to those of skill in the art.

Additionally, the engine control unit 104 may be provided as a single component or a collection of operably coupled components, and may include digital circuitry, analog circuitry, or a hybrid combination of the two types. When in a multi-component form, the engine control unit 104 may have one or more components that are remotely located in a distributed arrangement relative to other components. The engine control unit 104 may include a plurality of processing units arranged to operate independently in a pipeline processing arrangement, a parallel processing arrangement, or the like. In one embodiment, the engine control unit 104 includes several programmable micro-processing units of the solid state integrated circuit type distributed throughout the vehicle system 100, each including one or more processing units and non-transitory memory. For the depicted embodiment, the engine control unit 104 includes a computer network interface to facilitate communication between the various system control units using standard Controller Area Network (CAN) communications or the like. It should be understood that the depicted modules or other organizational units of the engine control unit 104 refer to certain operational logic that performs the indicated operations, which may be implemented in physically separate controllers of the engine control unit 104 and/or may be virtually implemented in the same controller.

The description herein, including the modules and/or organizational units, emphasizes the structural independence of the aspects of the engine control unit 104 and illustrates one grouping of operations and responsibilities of the engine control unit 104. Other groupings that perform similar overall operations are understood to be within the scope of the present application. The modules and/or organizational units may be implemented in hardware and/or as computer instructions on a non-transitory computer-readable storage medium, and may be distributed across various hardware or computer-based components.

Exemplary and non-limiting implementation elements of modules and/or organizational units of the engine control unit 104 include: a sensor providing any of the values determined herein; a sensor providing any value preceding the value determined herein; data link and/or network hardware including communication chips, oscillation crystals, communication links, cables, twin-stranded wires, coaxial wires, shielded wires, transmitters, receivers and/or transceivers; a logic circuit; a hard-wired logic circuit; a reconfigurable logic circuit in a particular non-transient state configured according to a module specification; any actuator, including at least an electrical actuator, a hydraulic actuator, or a pneumatic actuator; a solenoid; an operational amplifier; analog control elements (springs, filters, integrators, adders, dividers, gain elements); and/or a digital control element.

Engine control unit 104 and/or any of its constituent processors/controllers may include one or more signal conditioners, modulators, demodulators, Arithmetic Logic Units (ALUs), Central Processing Units (CPUs), limiters, oscillators, control clocks, amplifiers, signal conditioners, filters, format converters, communication ports, clamping circuits, delay devices, memory devices, analog-to-digital (a/D) converters, digital-to-analog (D/a) converters, and/or various circuits or functional components for performing the desired communication as will occur to those of skill in the art.

As shown in FIG. 1, the engine control unit 104 is operatively connected to various components of the vehicle system 100, including, for example, the engine 102, the ignition system 106, and/or various accessories or systems (not shown). Such a connection may allow information, data, and/or commands to be communicated between the engine control unit 104 and components of the vehicle system 100 used in connection with the operation and performance of the vehicle system 100.

The first ignition device 120 and the second ignition device 126 may each comprise one of a spark plug, a diesel pilot ignition device, a plasma ignition device, a laser ignition device, a thermal ignition device, a non-thermal ignition device, or other types of ignition devices.

Fig. 2 is a block diagram of a process for igniting fuel with the first ignition device 122 and/or the second ignition device 126 of the vehicle system 100. In block 200, the engine control unit 104 determines a first combustion condition. In block 204, the engine control unit 104 operates the first ignition device 122 to ignite the fuel in the pre-combustion chamber 122 and operates the second ignition device 126 to ignite the fuel in the main combustion chamber 128. Alternatively, in block 206, the engine control unit 104 operates the second ignition device 126 to ignite the fuel in the main combustion chamber 128, wherein the first ignition device 122 is not operated. In block 208, if the first combustion condition is not satisfied, the engine control unit 104 determines a second combustion condition. In block 210, the engine control unit 104 operates only the first ignition device 122 to ignite the fuel in the pre-combustion chamber 122.

FIG. 3 illustrates a first combustion condition 200, the first combustion condition 200 including an engine cold start event 302, an ignition failure event 304, a misfire event 306, a knock event 308, an under-burned mixture event 310, and a low engine load event 312. The engine control unit 104 and the ignition system 106 are configured to detect a first combustion condition 200.

The cold start event 302 will now be further described as shown in FIG. 4. The cold start event 302 includes parameters such as engine coolant temperature 402, engine oil temperature 404, engine speed 406, engine operating conditions 408, and crank conditions 410. The cold start event 302 may be determined in a variety of ways, and different criteria may be employed to make such a determination.

The engine oil temperature 404 may be used to determine the cold start event 302. When the engine oil temperature 404 is less than the engine oil temperature threshold, then the cold start event 302 is present. The viscosity of engine oil increases as its temperature decreases. During cold start conditions, significantly more battery power is required to crank the engine due to the viscosity of the engine oil, so the crank speed decreases as the engine oil temperature decreases.

Additional temperatures may be employed to determine the cold start event 302. For example, the engine coolant temperature 402 may indicate whether the engine has recently been operated, thereby providing an indirect measure of engine oil temperature. When the engine coolant temperature 402 is less than the engine coolant temperature threshold, then the cold start event 302 is present. Generally, engine oil temperature 404 varies primarily with engine output, while engine coolant temperature 402 varies with engine output, airflow, and radiator capacity. Thus, the engine oil temperature 404 is largely independent of the engine coolant temperature 402, except that when the oil temperature 404 heats up, the coolant temperature 402 is likely to heat up.

Alternatively or in addition, the engine speed 406 may be employed to determine the cold start event 302. The cold start event 302 also includes the engine speed 406 being less than the engine speed threshold, in which case the controller temperature will be less than the ambient air temperature.

Alternatively or in addition, engine operating conditions 408 may be employed to determine the cold start event 302. The engine operating conditions 408 include the engine being in a shut-down or non-operating condition.

Alternatively or in addition, the crank condition 410 may be employed to determine the cold start event 302. The cranking condition 410 includes the crankshaft speed being less than a threshold speed. The low battery voltage may contribute to the cranking condition 410 including the crankshaft speed being less than the threshold speed.

FIG. 5 illustrates a second combustion condition 208, which second combustion condition 208 includes a comparison of a condition from the first combustion condition 200 to a corresponding threshold. The engine control unit 104 and the ignition system 106 are configured to detect a second combustion condition 208, which should now be further described. The second combustion condition 208 includes one or more parameters, such as engine coolant temperature 402, engine oil temperature 404, engine speed 406, engine operating conditions 408, and cranking conditions 410. The engine coolant temperature 402 is greater than an engine coolant temperature threshold, the engine oil temperature 404 is greater than an engine oil temperature threshold, the engine speed 406 is greater than an engine speed threshold, the engine operating condition 408 is an operating or running condition of the engine 102, and the cranking condition 410 includes the crankshaft speed being greater than a threshold speed. In response to the second fuel condition 208, the ecu 104 operates only the first ignition device 122 to ignite the fuel in the pre-combustion chamber 122.

As previously mentioned, the first combustion condition 200 may also include an ignition failure event 304. The ignitor failure event 304 includes the first ignitor 120 failing to ignite fuel in the pre-combustion chamber 122 of the cylinder 124.

As previously mentioned, the first combustion condition 200 may also include a misfire event 306. The misfire event 306 includes the first ignition device 120 or the second ignition device 126 not properly firing during operating conditions of the engine 102. In one form, the engine control unit 104 may disable the ignition system 106 during one combustion cycle associated with the cylinder 124 and, after completion of one combustion cycle, re-enable the ignition system 106 to ignite fuel with either or both of the first and second ignition devices 120, 126 to operate the engine 102.

The first combustion condition 200 may also include a knock event 308. The presence of knock generated during operation of the engine 102 may be due, at least in part, to in-cylinder temperatures and the characteristics of the fuel used. In-cylinder temperatures during combustion events are also generally likely to be associated with oxides of Nitrogen (NO)_x) Is associated with a potential increase in the amount of nitrogen oxides. Further, as in-cylinder temperature increases, the engine knocks and NO is produced_xThe amount of (c) may also be increased.

The first combustion condition 200 may also include an insufficient combustion mixture event 310. The under-burned mixture event 310 is a lean-burned mixture event determined in response to at least one of an air-fuel ratio of the burned mixture, a lambda sensor output, and an engine-out NOx sensor output.

The first combustion condition 200 may also include a low engine load event 312. The engine load event 312 includes one or more of: the engine load is less than the engine load threshold; the intake manifold pressure is less than an intake manifold pressure threshold; and the cylinder pressure is less than the cylinder pressure threshold.

The engine control unit 104 may operate with the ignition system 106 to determine ionization conditions in the main combustion chamber 128. Specifically, the second ignition device 126 may operate as an ion sensor to determine ionization conditions in the main combustion chamber 128. In this way, the second ignition device 126 detects the quality of the fuel combustion, the start of the fuel combustion, and the location of peak pressure in the main combustion chamber 128.

Various aspects of the present disclosure are contemplated. According to one aspect, a method comprises: determining a first combustion condition of the internal combustion engine; an ignition system comprising a first ignition device for igniting fuel in a pre-combustion chamber of a cylinder and a second ignition device for igniting fuel in a main combustion chamber of the cylinder; and an engine control unit configured to initiate ignition with the first ignition device independently of the second ignition device; and in response to a first combustion condition: (i) igniting the fuel with the first ignition device and the second ignition device; or (ii) igniting the fuel with the second ignition device to operate the engine without igniting the fuel with the first ignition device.

In one embodiment, the method comprises: determining an occurrence of a second combustion condition associated with operation of the internal combustion engine; and operating the engine with only the first ignition device igniting fuel in response to the second combustion condition. In a refinement of the embodiment, the first combustion condition comprises at least one of: an engine cold start event, an ignition failure event, a misfire event, a knock event, an under-burned mixture event, and a low engine load event. In another refinement of the embodiment, the first combustion condition comprises an engine cold start event, wherein the cold start event is determined in response to one or more of: the engine coolant temperature is less than an engine coolant temperature threshold; the engine oil temperature is less than the engine oil temperature threshold; the engine speed is less than the engine speed threshold; the running state of the internal combustion engine is an off state; and the cranking condition of the internal combustion engine indicates that the crankshaft rotation speed is less than the threshold rotation speed. In a further refinement of the embodiment, the second combustion condition includes one or more of: the engine coolant temperature is greater than an engine coolant temperature threshold; the engine oil temperature is greater than the engine oil temperature threshold; the engine speed is greater than the engine speed threshold; the engine is in a running state; and the cranking condition indicates that the crankshaft speed is greater than the threshold speed.

In one embodiment, the first combustion condition is an ignition-failure event, and the ignition-failure event includes a failure of the first ignition to ignite the fuel in the pre-combustion chamber. In a refinement of the embodiment, the first combustion condition is a misfire event. In another refinement of the embodiment, the first combustion condition is an under-burned mixture event, and the under-burned mixture event is a lean-burned mixture event determined in response to at least one of an air-fuel ratio of the combustion mixture, a lambda sensor output, and an engine-out NOx sensor output. In yet another refinement of the embodiment, the ignition system is disabled for one combustion cycle associated with the cylinder upon detection of a misfire event; and after completion of one combustion cycle, reactivating the ignition system to ignite the fuel with both the first ignition device and the second ignition device to operate the engine.

In one embodiment, the method further comprises determining ionization conditions in the main combustion chamber with a second ignition device.

In one embodiment, the first ignition device and the second ignition device comprise one of a spark plug, a diesel pilot ignition device, a plasma ignition device, a laser ignition device, a thermal ignition device, or a non-thermal ignition device.

In another aspect, a system comprises: an internal combustion engine; an ignition system comprising a first ignition device associated with a pre-combustion chamber of a cylinder and a second ignition device associated with a main combustion chamber of the cylinder; an engine control unit operatively connected to both the internal combustion engine and the ignition system, the engine control unit configured to ignite fuel of the cylinder with the first ignition device independently of igniting fuel with the second ignition device; wherein the engine control unit is configured to determine an occurrence of at least one combustion condition associated with an operating condition of the engine, the engine control unit further configured to, in response to the occurrence of the at least one combustion condition: (i) igniting the fuel for combustion with both the first ignition device and the second ignition device; or (ii) igniting the fuel for combustion using only the second ignition device to operate the engine.

In one embodiment, the system includes an engine control unit configured to determine an occurrence of at least one second combustion condition associated with operation of the engine; and wherein the engine control unit is further configured to operate the engine using only the first ignition device to ignite the fuel in response to the second combustion condition.

In one embodiment, the at least one combustion condition includes one or more of: an engine cold start event, an ignition failure event, a misfire event, a knock event, an under-burned mixture event, and an engine load event. In one refinement, the at least one combustion condition is an engine cold start event, and the engine cold start event is determined in response to one or more of: the engine coolant temperature is less than an engine coolant temperature threshold; the engine oil temperature is less than the engine oil temperature threshold; the engine speed is less than the engine speed threshold; the running state of the internal combustion engine is an off state; and the cranking condition indicates that the crankshaft speed is less than the threshold speed.

In one embodiment, the second combustion condition comprises one or more of: the engine coolant temperature is greater than an engine coolant temperature threshold; the engine oil temperature is greater than the engine oil temperature threshold; the engine speed is greater than the engine speed threshold; the operating state of the internal combustion engine is an open state; and the cranking condition indicates that the crankshaft speed is greater than the threshold speed.

In one embodiment, the first combustion condition is an ignitor failure event and the ignitor failure event is a failure of the first ignitor to ignite fuel in the pre-combustion chamber.

In one embodiment, the first combustion event is a misfire event and the engine control unit is configured to: detecting a misfire event and disabling an ignition system in one combustion cycle associated with a cylinder; and after completion of one combustion cycle, the engine control unit is configured to reactivate the ignition system to operate the engine with both the first ignition device and the second ignition device igniting the fuel.

In one embodiment, the first combustion event is an under-burned mixture event, and the under-burned mixture event is a lean-burned mixture event determined in response to at least one of air-fuel ratio, lambda sensor output, and NOx sensor output.

In one embodiment, the engine control unit is configured to disable the ignition system in response to a misfire event, and the engine control unit is configured to enable the ignition system to ignite the fuel with both the first and second ignition devices in response to determining that the misfire event has concluded.

In one embodiment, the engine load event includes the engine load being less than an engine load threshold, the intake manifold pressure being less than an intake manifold pressure threshold, and the cylinder pressure being less than a cylinder pressure threshold.

In one embodiment, the second ignition device is further configured to sense an ionization condition in the combustion chamber.

In one embodiment, the first ignition device and the second ignition device comprise one of a spark plug, a diesel pilot ignition device, a plasma ignition device, a laser ignition device, a thermal ignition device, or a non-thermal ignition device.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described. Those skilled in the art will appreciate that many modifications are possible in the exemplary embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

In reading the claims, it is contemplated that when words such as "a," "an," "at least one," or "at least a portion" are used, it is not intended that the claims be limited to only one item unless specifically stated to the contrary in the claims. When the language "at least a portion" and/or "a portion" is used, an item can include a portion and/or the entire item unless specifically stated to the contrary.

It should be understood that no claim element herein should be construed in accordance with the provisions of 35 u.s.c. § 112(f), unless the phrase "means for. The schematic flow chart diagrams and method diagrams described above are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of representative embodiments. Other steps, sequences of steps, and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Furthermore, reference throughout this specification to "one embodiment," "an example embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment," "in an example embodiment," and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

Additionally, the format and symbols employed are provided to explain the logical steps of the diagram and are understood not to limit the scope of the method illustrated by the diagram. Although various arrow types and line types may be employed in the diagram, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and program code.