WO2024124191A1

WO2024124191A1 - Management of ignition energy in hydrogen fueled engines

Info

Publication number: WO2024124191A1
Application number: PCT/US2023/083216
Authority: WO
Inventors: J. Steven Kolhouse; Hui Xu; David J. Stroh; Daniel J. O'connor; Douglas L. Sprunger
Original assignee: Cummins Inc.
Priority date: 2022-12-09
Filing date: 2023-12-08
Publication date: 2024-06-13

Abstract

Systems and methods provided herein relate to managing ignition energy in a hydrogen fueled engine. A method includes: receiving data corresponding to an ignition system of at least one cylinder of a hydrogen fueled engine; determining, based on comparing the data to a first threshold, that residual ignition energy is present in the ignition system; and, responsive to determining that the residual ignition energy is present in the ignition system, causing the ignition system to use at least one residual ignition energy mitigation process comprising at least one of a charge clearing discharge process, a controlled leakage event, or ceasing a restrike from the ignition system.

Description

MANAGEMENT OF IGNITION ENERGY IN HYDROGEN FUELED

ENGINES

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This P.C.T. Patent Application claims the benefit to and priority to U.S. Provisional Patent Application No. 63/431,463, filed December 9, 2022, which is incorporated herein by reference in its entirety and for all purposes.

TECHNICAL FIELD

[0002] The present disclosure relates to hydrogen fueled engine systems. More particularly, the present disclosure relates to systems and methods for managing ignition energy, and particularly residual ignition energy, in a hydrogen fueled spark ignition engine.

BACKGROUND

[0003] A hydrogen internal combustion engine (“Hydrogen ICE”) combusts hydrogen fuel to power a system (e.g., a vehicle, stationary equipment, etc.). The engine includes one or more engine cylinders for combusting the hydrogen and generating power. Each cylinder may include an ignition assist device, such as a spark plug, for igniting the hydrogen within the cylinder. When a spark plug is “fired” (e.g., electrically charged), a portion of the energy provided to the spark plug may become “trapped” and remain in the spark plug. The trapped energy or “residual ignition energy” may have enough energy to cause an uncontrolled ignition event in the cylinder. This uncontrolled combustion event may lead to damage in the engine system via uncontrolled vibrations in the cylinder(s), undesired combustion characteristics that lead to undesired emissions, and other adverse effects on the system.

SUMMARY

[0004] One embodiment relates to a method. The method includes: receiving data corresponding to an ignition system of at least one cylinder of a hydrogen fueled engine; determining, based on comparing the data to a first threshold, that residual ignition energy is present in the ignition system; and responsive to determining that the residual ignition energy is present in the ignition system, causing the ignition system to use at least one residual ignition energy mitigation process comprising at least one of a charge clearing discharge process, a controlled leakage event, or ceasing a restrike from the ignition system.

[0005] Another embodiment relates to a system. The system includes an ignition system coupled to a controller. The controller includes one or more processors and one or more memory devices storing instructions that, when executed by the one or more processors, cause the one or more processors to perform operations. The operations include: receiving data regarding at least one operating condition of the engine and data regarding at least one environmental condition regarding the system; comparing at least one of the data regarding the at least one operating condition of the engine to a first threshold or the data regarding the at least one environmental condition to a second threshold; determining that residual ignition energy is present in the ignition system based on at least one of: the data regarding the at least one operating condition of the engine is outside a first desired operating range, or the data regarding the at least one environmental condition is outside a second desired operating range; and, responsive to determining that the residual ignition energy is present in the ignition system, causing the ignition system to implement at least one residual ignition energy mitigation process.

[0006] Another embodiment relates to a non-transitory computer readable media comprising instructions stored thereon that, when executed by one or more processors of a processing circuit, cause the one or more processors to perform operations. The operations include receiving data regarding an ignition system of a hydrogen fueled engine; determining that residual ignition energy is present in the ignition system based on comparing the data regarding the ignition system to a first threshold; and causing the ignition system to implement at least one residual ignition energy mitigation process responsive to determining that the residual ignition energy is present in the ignition system.

[0007] Numerous specific details are provided to impart a thorough understanding of embodiments of the subject matter of the present disclosure. The described features of the subject matter of the present disclosure may be combined in any suitable manner in one or more embodiments and/or implementations. In this regard, one or more features of an aspect of the invention may be combined with one or more features of a different aspect of the invention. Moreover, additional features may be recognized in certain embodiments and/or implementations that may not be present in all embodiments or implementations.

BRIEF DESCRIPTION OF THE FIGUES

[00011 FIG. l is a schematic view of a block diagram of a vehicle system, according to an example embodiment.

[0002] FIG. 2 is a block diagram of the controller of FIG. 1 coupled to various vehicle components, systems, and/or devices, according to an example embodiment.

|0003] FIG. 3 is a flow diagram of a method of monitoring ignition energy of one or more cylinders of the engine of FIG. 1, according to an example embodiment.

[0004] FIG. 4 is a flow diagram of a method of determining an ignition energy state of one or more cylinders of the engine of FIG. 1, according to an example embodiment.

[0005] FIG. 5 is a flow diagram of a method of controlling one or more ignition systems of the engine of FIG. 1, according to an example embodiment.

[0006] FIG. 6 is a graph depicting an air to fuel ratio versus a minimum ignition energy.

DETAILED DESCRIPTION

[0007| Following below are more detailed descriptions of various concepts related to, and implementations of methods, apparatuses, and systems for controlling and diagnosing hydrogen fueled spark-ignition internal combustion engines. The systems and methods described herein may be applicable to a variety of different coil ignition systems, such as single coil ignition systems, dual coil ignition systems, three or other multi- coil ignition systems, etc. Generally, however, the present disclosure relates to ignition systems implemented with hydrogen fueled spark-ignition engines. Before turning to the Figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the Figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting. [0008| As used herein, a “parameter,” “parameter value,” and similar terms, in addition to the plain meaning of these terms, refer to an input, output, or other value associated with a component of the systems described herein. For example, a parameter may include a sensor value detected by an actual sensor or determined by a virtual sensor. A parameter may include a value, control setting, or other control signal used by the control system to control one or more components described herein. Thus, a parameter may include data or information.

[0009] As used herein, “fire,” “ignite,” “strike,” and similar terms refer to an ignition device, such as a spark plug, receiving an electrical charge (e.g., ignition energy) thereby causing the ignition device to spark. In the spark plug configuration, the “spark” refers to an electrical current that is formed between two electrodes separated by an air gap when the spark plug receives the ignition energy. A “firing event” may include providing a command to an ignition device to generate a spark and/or providing the ignition energy to the ignition device thereby causing the spark.

|0010] Ignition systems employ coils comprising a primary and a secondary winding, per spark plug or ignitor. The ignition system also includes high voltage diodes that allow current to flow from the coil to the ignitor. While the diodes prevent current from flowing into the opposite direction to prevent unwanted discharge during an initial charging of the primary coil, they also introduce an unintended consequence - a “trapped” or residual charge between the diodes and the ignitor. The trapped charge may cause undesirable consequences. For example, the trapped charge may accumulate during successive coil discharges or “firing events” and breakdown during unwanted times, such as during the intake stroke of a spark ignition engine. Accordingly, premature sparks can occur that may cause damage to the engine due to unwanted combustion. The systems and methods described herein relate to discharging the trapped charge in an ignition system.

[0011] Beneficially and as described herein, a controller or control system may detect and/or determine the presence of residual ignition energy in one or more ignition systems (e.g., spark plugs). In some embodiments, the controller may initiate a residual ignition energy mitigation mode to discharge the residual ignition energy that is trapped in the spark plug. In some embodiments, a passive residual ignition energy mitigation may be used to discharge the residual ignition energy without action by the controller.

[0012] As described more fully herein, according to various exemplary embodiments, systems and methods of releasing the trapped charge may include eliminating transient voltage (i.e., restriking), introducing a small “trapped charge clearing” discharge (e.g., an additional or specifically commanded firing of the ignitor), and increasing the dwell time of the restrike as soon as a blowout (described more fully herein) has been detected to create a controlled breakdown. Other exemplary embodiments may include providing flow paths for the trapped charge, such as by providing a diode with a controlled leakage to create a pathway for discharging or dissipating the trapped charge. Further exemplary embodiments may include adjusting one or more ignition system parameters, such as spark timing, spark energy, spark duration, and/or multi-spark capability. As described herein, these methods can be utilized alone, in combination, and/or according to a predefined priority order as well as with other processes or methods to clear or substantially clear the trapped charge.

|0013] As described herein, a hydrogen fueled, spark-ignition internal combustion engine may include a cylinder block having one or more cylinders. Each of the cylinders includes a spark-ignition component or ignition assist device, such as a spark plug. A control system or controller is coupled to the ignition assist device (e.g., via one or more wires or a wired connection). The control system may monitor one or more parameters of the components of the engine using one or more sensors (e.g., actual sensors and/or virtual sensors) to collect and/or determine sensor data. The control system may analyze the sensor data and compare the analyzed sensor data with one or more thresholds. The control system may determine that one or more of the spark plugs may have a “trapped” or residual ignition energy (e.g., electrical charge remaining in the spark plug after a firing event, etc.) based on the analyzed sensor data exceeding a maximum threshold, being below a minimum threshold, or otherwise not falling within a predefined desired/acceptable range. The residual ignition energy may adversely impact the performance of the engine, for example, by causing an uncontrolled combustion in a cylinder. The uncontrolled combustion may cause physical damage to the cylinder and/or decrease fuel efficiency, decrease engine power output, and so on. The controller may mitigate residual ignition energy by employing one of the methods briefly described above.

[0014] Technically and beneficially, the systems, methods, and apparatuses described herein provide an improved control system that monitors and diagnoses residual ignition energy in an ignition system. The control system described herein advantageously utilizes a particular control strategy to mitigate against residual ignition energy. Further, the systems and methods described herein provide a technical solution to the technical problem of enabling a modified operating mode for an ignition system of an engine system when residual ignition energy is determined to be present in the ignition system by using a particular computer-based process that advantageously prevent an uncontrolled combustion caused by the residual ignition energy. Advantageously, the modified operating mode is enabled automatically (e.g., without user input) and may be dynamically adjusted based on an operating condition(s) of the engine system.

[0015] In an example scenario, a control system (e.g., a controller, a vehicle controller, etc.) is structured to detect and/or determine the presence of residual ignition energy in an ignition system (e.g., a spark plug). The control system may employ one or more residual ignition energy mitigation methods to discharge the residual ignition energy. The control system may determine to use one or more of the residual ignition energy mitigation methods based on a configuration of the engine system and/or ignition system and/or one or more operating parameters of the engine system and/or ignition system.

10016] Referring now to FIG. 1, a schematic view of a block diagram of a vehicle system 100 is shown, according to an example embodiment. The system 100 includes an engine 110, a fuel system 120 coupled to the engine 110, an operator input/output (VO) device 130, vehicle subsystems 135, and a controller 140, where the controller 140 is communicably coupled to each of the aforementioned components. In the configuration of FIG. 1, the system 100 is included in a vehicle. The vehicle may be any type of on-road or off-road vehicle including, but not limited to, wheel-loaders, fork-lift trucks, line-haul trucks, midrange trucks (e.g., pick-up truck, etc.), sedans, coupes, tanks, airplanes, boats, and any other type of vehicle. In another embodiment, the system 100 may be embodied in a stationary piece of equipment, such as a power generator or genset. All such variations are intended to fall within the scope of the present disclosure.

[0017] In the example shown, the engine 110 is a hydrogen fueled, spark-ignition (SI) internal combustion engine. In other embodiments, the engine 110 may use a hydrogen fuel mixed with another fuel type, such as a hydrocarbon fuel (e.g., diesel, gasoline, natural gas, etc.). The blended fuel type may have less hydrogen content (e.g., concentration, percent by volume or weight, etc.) than a pure hydrogen fuel. In any of these embodiments, the fuel used by the engine 110 has a hydrocarbon content below a predetermined threshold. In the example shown in FIG. 1, the engine 110 is a hydrogen fueled, SI internal combustion engine. The engine 110 may include one or more cylinders 112. As shown in FIG. 1, the engine 110 includes six cylinders 112. However, it should be understood that the engine 110 may include more or fewer cylinders 112 (e.g., 4 cylinders, 8 cylinders, etc.). Further, the cylinders 112 may be arranged in any cylinder configuration (e.g., inline cylinders, V- cylinders, etc.). Each cylinder may include an ignition system 114. The ignition systems 114 each include an ignition assist device and, particularly, a spark plug 116.

[0018] In some embodiments, the ignition systems 114 may be controlled by the controller 140. For example, one or more parameters of the spark plug 116 may be controlled by the controller 140. The parameters of the spark plug 116 may include a spark timing (when a spark is commanded from the spark plug), a spark energy, a spark duration (how long the spark is commanded for), and/or multi-spark capability (whether multiple sparks are commanded within a certain period of time or operating period). The spark timing may define the time the spark plug 116 is ignited relative to a previous spark event and/or relative to a cylinder cycle. The spark energy may define an amount of energy provided to the spark plug 116 (e.g., to ignite the spark plug 116). The spark duration may define the time that the spark energy is provided to the spark plug 116. The multi-spark capability may define the ability of the spark plug 116 to fire multiple times during a particular operating period and, namely, a cylinder cycle. More specifically, the multi-spark capability may define a spark timing, a spark energy, and/or a spark duration of multiple firing events during a single cylinder cycle. [00191 The fuel system 120 is configured to provide fuel (e.g., hydrogen) to the engine 110. The fuel system 120 may include a fuel storage device (e.g., a hydrogen fuel tank) and one or more fuel injection devices configured to provide the fuel to the engine 110. In some embodiments, the fuel system 120 may use one or more methods for providing fuel to the engine 110. For example, the fuel system 120 may provide fuel to the engine via an upstream/throttle injection, a port injection, and/or a direct injection (among potentially others).

[0020] In some embodiments, the fuel system 120 may be controlled by the controller 140. For example, one or more parameters of the fuel system 120 may be controlled by the controller 140. The parameters of the fuel system may include a fuel injection amount, a fuel injection timing, a fuel rail pressure, etc. The fuel injection amount may define an amount of fuel injected into a cylinder 112 for each cylinder cycle. The fuel injection timing may define the time the fuel is injected into a cylinder 110 relative to a previous fuel injection and/or relative to a cylinder cycle. The fuel rail pressure may define a pressure of the fuel provided to the engine 110.

[0021] Referring still to FIG. 1, an operator input/output (I/O) device 130 is also shown. The operator I/O device 130 may be coupled to the controller 140, such that information may be exchanged between the controller 140 and the I/O device 130, wherein the information may relate to one or more components of FIG. 1 or determinations (described below) of the controller 140. The operator I/O device 130 enables an operator of the system 100 to communicate with the controller 140 and one or more components of the system 100 of FIG. 1. For example, the operator input/output device 130 may include, but is not limited to, an interactive display, a touchscreen device, one or more buttons and switches, voice command receivers, etc. In this way, the operator input/output device 130 may provide one or more indications or notifications to an operator, such as a malfunction indicator lamp (MIL), etc. Additionally, the vehicle may include a port that enables the controller 140 to connect or couple to a scan tool so that fault codes and other information regarding the vehicle may be obtained.

[0022] The vehicle subsystems 135 may include one or more components, systems, and/or devices included with the vehicle, such as mechanically driven or electrically driven vehicle components. The vehicle subsystems 135 may include, but are not limited to, an HVAC system, lights, pumps, fans, and so on.

[0023] In some embodiments, the system 100 also includes one or more components positioned downstream of the engine 110 and configured to receive exhaust output by the engine 110. In some embodiments, the system 100 includes a turbocharger configured to receive exhaust output by the engine 110 and compress intake fluid (e.g., air, etc.) provided to the engine 110. In some embodiments, the system 100 includes an aftertreatment system having components used to convert exhaust emissions, such as selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), a diesel exhaust fluid (DEF) doser with a supply of diesel exhaust fluid, a plurality of sensors for monitoring the aftertreatment system (e.g., a nitrogen oxide (NOx) sensor, temperature sensors, etc.), and/or still other components.

[00241 The controller 140 is structured to control, at least partly, the operation of the system 100 and associated sub-systems, such as the engine 110 and the operator input/output (I/O) device 130. Communication between and among the components may be via any number of wired or wireless connections. For example, a wired connection may include a serial cable, a fiber optic cable, a CAT5 cable, or any other form of wired connection. In comparison, a wireless connection may include the Internet, Wi-Fi, cellular, radio, etc. In one embodiment, a controller area network (CAN) bus provides the exchange of signals, information, and/or data. The CAN bus includes any number of wired and wireless connections. Because the controller 140 is communicably coupled to the systems and components of FIG. 1, the controller 140 is structured to receive data from one or more of the components shown in FIG. 1. The structure and function of the controller 140 is further described in regard to FIG. 2.

|0025J As the components of FIG. 1 are shown to be embodied in the system 100 which is included in a vehicle, the controller 140 may be structured as one or more electronic control units (ECUs), such as one or more microcontrollers. The controller 140 may be separate from or included with at least one of a transmission control unit, an exhaust aftertreatment control unit, a powertrain control module, an engine control module, etc. [0026| As shown, one or more sensors 125 are included in the system 100. The number, placement, and type of sensors included in the system 100 is shown for example purposes only. That is, in other configurations, the number, placement, and type of sensors may differ. For example, the sensors 125 may be located in or proximate the engine 110, upstream of the engine 110 and/or downstream of the engine 110. It should be understood that the location of the sensors may vary. The sensors 125 may be engine sensors configured to detect and/or determine one or more parameters of the engine 110, such as an engine torque, an engine power, an engine speed (e.g., in rotations per minute), an engine exhaust gas value (e.g., engine exhaust manifold pressure). For example, the sensors 125 may include a torque sensor configured to detect and/or determine an engine torque, a pressure sensor configured to detect and/or determine an exhaust manifold pressure, an engine mounted accelerometer or noise sensor configured to detect and/or determine engine knock, a cylinder pressure sensor configured to detect and/or determine a pressure within a cylinder, and/or a cylinder ion sensor configured to detect and/or determine the presence or concentration of ions within a cylinder. Additional sensors may be also included with the system 100. The sensors may include sensors associated with other components of the vehicle (e.g., speed sensor of a turbo charger, fuel quantity and injection rate sensor, fuel rail pressure sensor, etc.).

[0027] In some embodiments, the sensors 125 may include one or more of a voltage sensor, a current sensor, or other sensor for measuring and/or determining residual ignition energy. For example, a voltage sensor may be used to measure a voltage across a spark plug 116. The voltage across the spark plug 116 may correspond to an amount of residual ignition energy stored at the spark plug 116.

10028] The sensors 125 may be real or virtual (i.e., a non-physical sensor that is structured as program logic in the controller 140 that makes various estimations or determinations). For example, an engine speed sensor may be a real or virtual sensor arranged to measure or otherwise acquire data, values, or information indicative of a speed of the engine 110 (typically expressed in revolutions-per-minute). The sensor is coupled to the engine (when structured as a real sensor) and is structured to send a signal to the controller 140 indicative of the speed of the engine 101. When structured as a virtual sensor, at least one input may be used by the controller 140 in an algorithm, model, lookup table, etc. to determine or estimate a parameter of the engine (e.g., power output, etc.). Any of the sensors 125 described herein may be real or virtual.

[0029] The controller 140 is coupled and, particularly communicably coupled, to the sensors 125. Accordingly, the controller 140 is structured to receive data from one more of the sensors 125 and provide instruct ons/informati on to the one or more sensors 125. The received data may be used by the controller 140 to control one or more components in the system 100 and/or for monitoring the system 100 and/or controlling one or more components of the system 100.

[0030] FIG. 2 is a block diagram of the controller of FIG. 1, according to an example embodiment. As shown, the controller 140 includes at least one processing circuit 202 having at least one processor 204 and at least one memory device 206, a sensor management circuit 210, an ignition system control circuit 212, a fuel system control circuit 214, and a communications interface 216. The controller 140 is structured to monitor the engine 110 and detect and/or determine a residual ignition energy in the ignition system 114. The controller 140 may further be configured to discharge the residual ignition energy. Methods for detecting and/or determining residual ignition energy in the ignition system 114 are described herein below.

[0031] In one configuration, the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 are embodied as machine or computer-readable media storing instructions that are executable by a processor, such as processor 204. The machine-readable media may include programmable logic. The computer readable media instructions may include code, which may be written in any programming language including, but not limited to, Java or the like and any conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program code may be executed on one processor or multiple remote processors. In the latter scenario, the remote processors may be connected to each other through any type of network (e.g., CAN bus, etc.). [00321 In another configuration, the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 are embodied as hardware units, such as one or more electronic control units. As such, the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 may be embodied as one or more circuitry components including, but not limited to, processing circuitry, network interfaces, peripheral devices, input devices, output devices, sensors, etc. In some embodiments, the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 may take the form of one or more analog circuits, electronic circuits (e.g., integrated circuits (IC), discrete circuits, system on a chip (SOCs) circuits, microcontrollers, etc.), telecommunication circuits, hybrid circuits, and any other type of “circuit.” In this regard, the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 may include any type of component for accomplishing or facilitating achievement of the operations described herein. For example, a circuit as described herein may include one or more transistors, logic gates (e.g., NAND, AND, NOR, OR, XOR, NOT, XNOR, etc.), resistors, multiplexers, registers, capacitors, inductors, diodes, wiring, and so on). The sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 may also include or be programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. The sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 may include one or more memory devices for storing instructions that are executable by the processor(s) of the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214. The one or more memory devices and processor(s) may have the same definition as provided below with respect to the memory device 206 and processor 204. In some hardware unit configurations, the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 may be geographically dispersed throughout separate locations in the system 100. Alternatively and as shown, the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 may be embodied in or within a single unit/housing, which is shown as the controller 140. [00331 In the example shown, the controller 140 includes the processing circuit 202 having the processor 204 and the memory device 206. The processing circuit 202 may be structured or configured to execute or implement the instructions, commands, and/or control processes described herein with respect to t the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214. The depicted configuration represents the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 being embodied as machine or computer-readable media storing instructions. However, as mentioned above, this illustration is not meant to be limiting as the present disclosure contemplates other embodiments where at least one of the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 is configured as a hardware unit. All such combinations and variations are intended to fall within the scope of the present disclosure.

[0034] The at least one processor 204 may be implemented as one or more single- or multichip processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), and/or suitable processors (e.g., other programmable logic devices, discrete hardware components, etc. to perform the functions described herein). A processor may be a microprocessor, a group of processors, etc. A processor also may be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some embodiments, the one or more processors may be shared by multiple circuits (e.g., the sensor management circuit 210, the ignition system control circuit 212, and/or the fuel system control circuit 214 may comprise or otherwise share the same processor which, in some example embodiments, may execute instructions stored, or otherwise accessed, via different areas of memory). Alternatively or additionally, the one or more processors may be structured to perform or otherwise execute certain operations independent of one or more co-processors. In other example embodiments, two or more processors may be coupled via a bus to enable independent, parallel, pipelined, or multi-threaded instruction execution. All such variations are intended to fall within the scope of the present disclosure. [00351 The at least one memory device 206 (e.g., memory, memory unit, storage device) may include one or more devices (e.g., RAM, ROM, Flash memory, hard disk storage) for storing data and/or computer code for completing or facilitating the various processes, layers and modules described in the present disclosure. For example, the memory device 206 may include dynamic random-access memory (DRAM). The memory device 206 may be communicably connected to the processor 204 to provide computer code or instructions to the processor 204 for executing at least some of the processes described herein. Moreover, the memory device 206 may be or include tangible, non-transient volatile memory or non-volatile memory. Accordingly, the memory device 206 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described herein.

[0036] The communications interface 216 may include any combination of wired and/or wireless interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wire terminals) for conducting data communications with various systems, devices, or networks structured to enable in-vehicle communications (e.g., between and among the components of the vehicle) and out-of-vehicle communications (e.g., with a remote server). For example and regarding out-of-vehicle/system communications, the communications interface 216 may include an Ethernet card and port for sending and receiving data via an Ethernet-based communications network and/or a Wi-Fi transceiver for communicating via a wireless communications network. The communications interface 216 may be structured to communicate via local area networks or wide area networks (e.g., the Internet) and may use a variety of communications protocols (e.g., IP, LON, Bluetooth, ZigBee, radio, cellular, near field communication).

[0037] The sensor management circuit 210 is structured or configured to control the operation of the sensors 125 and exchange information with the sensors 125. For example, the sensor management circuit 210 may be structured to generate one or more control signals and transmit the control signals to one or more sensors 125 (e.g., to acquire data, etc.). The control signals may cause the one or more sensors 125 to sense and/or detect the sensor data and/or provide the sensor data to the sensor management circuit 210. In some embodiments, the sensor management circuit 210 may be structured to estimate the sensor data (e.g., when the sensors 125 are virtual sensors). The “sensor data” may include temperature data (e.g., fluid temperature such as exhaust gas temperature or engine oil temperature, component temperature such as engine temperature, etc.), flow rate data (e.g., exhaust gas flow rate data, charge air flow rate, etc.), pressure data (e.g., engine cylinder pressure, coolant pressure, exhaust gas pressure, etc.), engine data (e.g., engine torque, engine speed, engine power, etc.), and/or other data related to the operation of the system 100, such as data indicative of residual ignition energy present in the ignition system 114. For example, the data may include one or more of an engine load, an engine speed, an engine torque, an exhaust manifold pressure, a cylinder pressure, an ion detection, a spark plug voltage, a spark plug current, a spark plug power, and/or other sensor data or information described herein. The data may be used to determine the presence of residual ignition energy in the ignition system 114, as described herein with respect to FIG. 3.

[0038] The ignition system control circuit 212 is structured to control the operation of the ignition system 114. The ignition system control circuit 212 may control the operation of the ignition system 114 based on a configuration of the ignition system (e.g., a single coil ignition system, a dual coil ignition system, etc.), a detected presence of residual ignition energy, and/or among other factors.

10039] In some embodiments, the ignition system control circuit 212 is configured to detect and/or determine a residual charge “blowout”. A “blowout” refers to a situation in which the spark has become prematurely extinguished, yet the ignition system 114 is unaware of the extinguishment. High or varying engine loads (i.e., turbulent engine operating conditions) may lead to blowout. During these turbulent engine conditions, the likelihood of the spark extinguishing can increase because of the strains on the engine 110. These strains may cause turbulence in the spark gap that extinguish the spark. However, the spark plugs 116 continue to discharge as if to sustain the spark, but such discharges are insufficient to re-initiate the spark. Due to successive discharges that do not cause a spark from the ignitor, a build-up of trapped charge may occur that can eventually lead to a breakdown event. A breakdown refers to the accumulated residual charge overcoming the resistance in the path between diodes and ignitor to cause or attempt to cause a spark from the ignitor. A breakdown may be undesirable due to its timing. For example, a breakdown can occur during an intake stroke of a cylinder cycle, which increases the possibility of a premature combustion and potential damage to the engine 110.

[0040] In some embodiments, the ignition system control circuit 212 is structured to use one or more residual ignition energy mitigation methods responsive to detecting and/or determining the presence of residual ignition energy trapped in the spark plug 116. The residual ignition energy mitigation methods may include a charge clearing discharge, a controlled leakage diode, a charge dump circuit, and/or an ignition system adjustment.

[0041] The charge clearing discharge method may include providing, by the controller 140, a command to the spark plug 116 to generate a spark (e.g., before an intake stroke of the cylinder cycle). The spark generated by the spark plug 116 causes the residual ignition energy to be used to generate the spark, thereby “clearing” or discharging the residual ignition energy. The controller 140 may use the charge clearing discharge method based on detecting and/or determining (e.g., based on sensor data from sensors 125) a high engine load. The controller 140 may cause the spark resulting from the charge clearing discharge to occur during a light load condition. The light load condition may include an exhaust stroke of the cylinder cycle.

[0042 [ The controlled leakage diode may include providing an electrical pathway for the residual ignition energy. In an example embodiment, a diode with a controlled leakage creates an electrical pathway for discharging or dissipating the trapped charge in the ignition system 114. In these embodiments, the residual ignition energy is passively discharged. However, in some embodiments, if the controller 140 detects and/or determines that a residual ignition energy value exceeds a corresponding threshold, the controller may use an additional residual ignition energy mitigation method. The controlled leakage diode advantageously continuously and without input from the controller 140. In some embodiments, the controlled leakage diode may be replaced and/or supplemented with a resistor that creates an electrical pathway for discharging or dissipating the trapped charge in the ignition system 114. [00431 The charge dump circuit method may include providing a charge dump circuit in the ignition system 114. The charge dump circuit may include a switch that is operable between an open position and a closed position (e.g., by the controller 140). When the switch is in the open position, the charge dump circuit allows the ignition system to operate normally. When the switch is in the closed position, the charge dump circuit connects the spark plug to ground such that the residual ignition energy discharges to ground. In an example embodiment, the charge dump circuit method may include providing a command to the ignition system 114 to close the switch of the charge dump circuit, such that the residual ignition energy freely flows to ground thereby clearing the residual ignition energy. The controller 140 may use the charge dump method responsive to detecting residual ignition energy in the ignition system 114.

[0044| As briefly described above, adjusting the ignition system 114 may include adjusting one or more parameters of the ignition system 114. In some embodiments, the ignition system 114 includes a single coil ignition system. In these embodiments, the controller 140 may adjust one or more of the spark timing, the spark energy, or the spark duration, of the ignition system 114. For example, the controller 140 may cause the ignition system to adjust a spark duration responsive to detecting and/or determining the presence of residual ignition energy. In other embodiments, the ignition system 114 includes a dual coil ignition system. In these embodiments, the controller 140 may adjust one or more of the spark timing, the spark energy, the spark duration, and/or the multi-spark capability of the ignition system 114. For example, the controller 140 may cause the ignition system 114 to enable a multispark function of the ignition system 114 responsive to detecting and/or determining the presence of residual ignition energy.

1 045] In some embodiments, the ignition system 114 may include the dual coil ignition system when the engine 110 is configured to use a blended hydrogen (e.g., hydrogen mixed with a hydrocarbon) fuel. Advantageously, the dual coil ignition system may be used to ignite the blended hydrogen fuel because the blended hydrogen fuel is more difficult to ignite compared to the pure hydrogen fuel. In pure or substantially pure hydrogen fuel systems, the ignition system may not include a dual coil system. In some embodiments, when the ignition system 114 includes a dual coil ignition system, the ignition system control circuit 212 may be structured to use dual coil ignition specific residual ignition energy mitigation methods in addition to and/or instead of any of the above-described residual ignition energy mitigation methods. The dual coil ignition specific residual ignition energy mitigation methods may include stopping restriking and increasing the dwell time of a restrike.

[0046] A “restrike” refers to the process of continuing to command discharges from the ignition system 114 for a spark. In the case of a blowout condition, the continuing discharges may increase the amount of residual ignition energy because the discharges are insufficient to re-initiate the spark.

(0047] When the ignition system 114 is configured as a dual coil ignition system, the controller 140 may detect and/or determine a blowout or potential blowout situation by receiving data indicative of current dropping to at or below a threshold. Responsive to detecting and/or determining the blowout condition, the controller 140 provides a command to stop demanding a spark (i.e., stop restriking). By providing the command to stop demanding a spark, the ignition system 114 discharging ceases (even with the spark extinguished), such that the accrual of more trapped charge is prevented or substantially prevented.

[0048| The controller 140 may be configured to increase the dwell time of a restrike responsive to detecting and/or determining a blowout or potential blowout situation. The “dwell time” refers to the charging time of an ignition coil in the ignition system 114. By increasing the dwell time, more energy is provided to a first coil of the dual coil ignition system. The dwell time may be increased beyond an original dwell time or first dwell time. The first dwell time may be approximately equivalent to a charge time sufficient to maintain a spark from the ignition system 114, which is less than the time required to cause (e.g., initiate) the spark from the ignitor.

10049] By increasing the energy provided to the first coil after the spark current has ceased, a relatively larger voltage in a second coil of the dual coil ignition system is induced. The increased voltage in the second coil causes a controlled breakdown and a subsequent firing of the ignition system 114. The controlled breakdown and subsequent firing of the ignition system 114 clears the residual ignition energy trapped in the ignition system 114.

[00501 The fuel system control circuit 214 is configured to control the operation of the fuel system 120. As described above, the fuel system control circuit 214 may adjust one or more parameters of the fuel system including at least one of a fuel injection amount, a fuel injection timing, a fuel rail pressure, etc.

[0051 ] FIG. 3 is a flow diagram of a method 300 of monitoring ignition energy of one or more cylinders of the engine of FIG. 1, according to an example embodiment. In particular, the method 300 relates to detecting (e.g., by one or more sensors 125) the presence of residual ignition energy in the ignition system 114. In some embodiments, the controller 140 and/or one or more components thereof, such as the sensor management circuit 210, is/are configured to perform method 300. For example, the controller 140 may be structured to perform the method 300, alone or in combination with other devices such as the sensors 125 and/or other components of the system 100. In some embodiments, the processes of the method 300 may be performed in a different order than as shown in FIG. 3. In some embodiments, the method 300 may include more or fewer processes than as shown in FIG. 3. In some embodiments, the processes of the method 300 may be performed concurrently, partially concurrently, or sequentially.

[0052] Referring to the method 300 in more detail, at process 302, the controller 140 receives first sensor data from the sensors 125. In some embodiments, the first sensor data includes data from one or more sensors 125 associated with the engine 110 and/or one or more components thereof, such as one or more cylinders 110 and/or one or more components of the ignition system 114. As described above, the sensor data may include an engine torque value, an engine power value, an engine exhaust pressure value, an engine acceleration value, a cylinder pressure value, a cylinder ion value, etc. The first sensor data may be indicative of residual ignition energy present in the ignition system 114. For example, the data may include one or more of an engine load, an engine speed, an engine torque, an exhaust manifold pressure, a cylinder pressure, an ion detection, a spark plug voltage, a spark plug current, a spark plug power, and/or other sensor data or information described herein. The correlation of the sensor data with residual ignition energy is described herein with respect to process 306.

[0053] At process 304, the controller 140 compares the first sensor data to a corresponding first threshold. For example, the first threshold may include an engine torque threshold, an engine power threshold, an engine exhaust pressure threshold, an engine acceleration threshold, a cylinder pressure threshold, a cylinder ion threshold, etc. If the first sensor data satisfies a corresponding threshold (e.g., less than a maximum threshold, greater than a minimum threshold, within a threshold range, within a desired operating range, etc.), the method may return to process 302. If the first sensor data does not satisfy a corresponding threshold or is outside a desired operating range (e.g., greater than a maximum threshold, less than a minimum threshold, outside a threshold range, etc.), the method continues to process 306.

[00541 At process 306, the controller 140 determines the presence of residual ignition energy in the ignition system 114 based on one or more first sensor values exceeding a corresponding threshold. In an example embodiment, the controller 140 may determine that a combustion misfire has occurred based on at least one of the engine torque value not satisfying a torque threshold (e.g., when the torque value is at or below the torque threshold or is outside a desired operating range of torque values) or the exhaust manifold pressure value not satisfying an exhaust manifold pressure threshold (e.g., when the exhaust manifold pressure value is at or below the exhaust manifold pressure threshold or is outside a desired operating range of exhaust manifold pressure values). The controller 140 may determine the presence of residual ignition energy in the ignition system 114 based on determining that a combustion misfire has occurred.

[0035] In another example embodiment, the controller 140 may determine that abnormal combustion knock is occurring based on an engine acceleration value not satisfying an engine acceleration threshold (e.g., when the engine acceleration value is at or below the engine acceleration threshold or is outside a desired operating range of engine acceleration values) or an engine noise value not satisfying an engine noise threshold (e.g., when the engine noise value is at or above the engine noise threshold or is outside a desired operating range of engine noise values). The controller 140 may determine the presence of residual ignition energy based on determining abnormal combustion knock is occurring.

[0056] In some embodiments, the controller 140 may determine the presence of residual ignition energy based on a cylinder pressure not satisfying a cylinder pressure threshold or when the cylinder pressure value is outside a desired operating range of cylinder pressure values. For example, if the cylinder pressure is above a maximum threshold or below a minimum threshold, the controller 140 may determine that residual ignition energy is present in the ignition system 114.

[0057] In some embodiments, the controller 140 may determine the presence of residual ignition energy based on an exhaust manifold pressure not satisfying an exhaust manifold threshold or when the exhaust manifold pressure is outside a desired operating range of exhaust manifold pressure values. For example, if the exhaust manifold pressure is above a maximum threshold or below a minimum threshold, the controller 140 may determine that residual ignition energy is present in the ignition system 114.

[0058] In some embodiments, the controller 140 may determine the presence of residual ignition energy based on an ion level not satisfying an ion level threshold or when the ion level is outside a desired operating range of ion level values. For example, if the ion level within a cylinder 110 is above a maximum threshold or below a minimum threshold, the controller 140 may determine that residual ignition energy is present in the ignition system 114.

[0859] Responsive to determining the presence of residual ignition energy in the ignition system 114, the controller 140 may provide an indication to a user. For example, the controller 140 may cause the operator I/O device 130 to display an indication of the presence of residual ignition energy in the ignition system 114. In some embodiments, the controller 140 may continue to the method 500 shown in FIG. 5.

[0060] FIG. 4 is a flow diagram of a method 400 of determining an ignition energy state of one or more cylinders of the engine of FIG. 1, according to an example embodiment. In this way, the ignition energy state may refer to the presence or absence of residual ignition energy. In particular, the method 400 relates to determining (e.g., based on sensor data) the presence of residual ignition energy in the ignition system 114. In some embodiments, the controller 140 and/or one or more components thereof is/are configured to perform method 400. For example, the controller 140 may be structured to perform the method 400, alone or in combination with other devices such as the sensors 125 and/or other components of the system 100. In some embodiments, the processes of the method 400 may be performed in a different order than as shown in FIG. 4. In some embodiments, the method 400 may include more or fewer processes than as shown in FIG. 4. In some embodiments, the processes of the method 400 may be performed concurrently, partially concurrently, or sequentially.

|006l] Referring to the method 400 in more detail, at process 402, the controller 140 receives engine operating conditions. The engine operating conditions may include sensor data, and/or one or more operating parameters of the engine 110. For example, the engine operating conditions may include an engine speed value, an engine load value, an air to fuel ratio provided to the engine (e.g., by the fuel system 120), etc.

[0062] At process 404, the controller 140 compares the engine operating conditions to a corresponding second threshold. For example, the second threshold may include an engine speed threshold, an engine load threshold, etc. If the engine operating conditions satisfies a corresponding threshold (e.g., less than a maximum threshold, greater than a minimum threshold, within a threshold range, within a desired operating range, etc.), the method 400 may continue to process 408. If the engine operating conditions does not satisfy a corresponding threshold or is outside a desired operating range (e.g., greater than a maximum threshold, less than a minimum threshold, outside a threshold range, etc.), the method continues to process 406.

[0063] At process 406, the controller 140 determines the presence of residual ignition energy in the ignition system 114 based on one or more engine operating condition values exceeding a corresponding threshold. For example, transients in the air-to-fuel ratio (e.g., “air-to-fuel ratio transient conditions”) provided to the engine may exceed a desired air-to- fuel ratio transient threshold. As utilized herein, “air-to-fuel ratio transient condition” refers to an operating condition in which the air-to-fuel ratio (AFR) provided to the engine 110 changes (e.g., increase, decreases, increases then decreases, decreases then increases, or some combination thereof) over a predefine period of time. In some embodiments, the AFR may be estimated based on a fueling command and an air intake command generated by the controller 140. More specifically, the AFR may be estimated based on a commanded amount of air (e.g., an air value) relative to a commanded amount of fuel (e.g., a fuel value). In other embodiments, the AFR may be determined based on a measured or sensed amount of air relative to a measured or sensed amount of fuel provided to the engine. The variability of the air to fuel ratio may cause an unintended blowout during a cylinder cycle, such as when the engine speed and/or the engine load is relatively low (i.e., below predefined low speed or low threshold values which may differ based on the engine size/configuration). The premature termination of the spark event (e.g., the unintended blowout) results in residual energy within the ignition system 114. Because transients in the air to fuel ratio occur increases with increased engine load and/or increased engine speed, the controller 140 may determine that the presences of residual energy within the ignition system 114 based on at least one of the engine load not satisfying an engine load threshold (e.g., when the engine load value is at or below the engine load threshold or is outside a desired operating range of engine load values) or the engine speed not satisfying an engine speed threshold (e.g., when the engine speed value is at or below the engine speed threshold or is outside a desired operating range of engine speed values).

10064] In an example embodiment, the engine load threshold may include, for example, a light load threshold corresponding to a light load condition and/or a heavy load threshold corresponding to a heavy load condition. When the engine operating conditions include an engine load, the controller 140 may determine that the engine is operating in a light load condition responsive to determining that the engine load is at or below the light load threshold. Similarly, the controller 140 may determine that the engine is operating in a heavy load condition responsive to determining that the engine load is at or above the heavy load threshold.

[00651 Responsive to determining the presence of residual ignition energy in the ignition system 114, the controller 140 may provide an indication to a user. For example, the controller 140 may cause the operator I/O device 130 to display an indication of the presence of residual ignition energy in the ignition system 114. In some embodiments, the controller 140 may continue to process 408 and/or to the method 500 shown in FIG. 5. [0066| At process 408, the controller 140 receives environmental conditions. The engine environmental conditions may include sensor data (e.g., from one or more sensors 125 configured as a humidity sensor, a moisture sensor, etc.), and/or environmental data received from a remote computing device (e.g., from a remote computing device via a telematics device of the vehicle and/or the communications interface 220). The remote computing device may be associated with an original equipment manufacturer of the system 100 and/or with another service provider. The environmental conditions may include an atmosphere humidity or an ambient humidity (e.g., a humidity value), an indication of rain (including an indication of whether rainwater is entering an air intake system of the engine 110), an ambient temperature (including an indication of whether condensation is forming on an air intake cooling system of the engine 110), etc.

[0067 { At process 410, the controller 140 compares the environmental conditions to a corresponding third threshold. For example, the third threshold may include a humidity threshold, a rainwater intake threshold, a condensation threshold, etc. If the environmental conditions satisfy a corresponding threshold or is outside a desired operating range (e.g., less than a maximum threshold, greater than a minimum threshold, within a threshold range, etc.), the method 400 may return to process 402. If the engine operating conditions does not satisfy a corresponding threshold or is outside a desired operating range (e.g., greater than a maximum threshold, less than a minimum threshold, outside a threshold range, etc.) the method 400 continues to process 412.

[0068| At process 412, the controller 140 determines the presence of residual ignition energy in the ignition system 114 based on one or more environmental condition values exceeding a corresponding threshold. One or more of the environmental conditions may be capable of resulting in residual ignition energy. For example, in-cylinder humidity (e.g., water content) may cause blowout, thereby resulting in residual ignition energy becoming trapped in the ignition system 114. In-cylinder humidity can result from atmospheric humidity, ingesting rainwater into the intake air system, and/or intake system condensation from cooling intake air. Accordingly, the controller 140 may determine that the presences of residual energy within the ignition system 114 based on at least one of the atmospheric humidity not satisfying an atmospheric humidity threshold (e.g., when the atmospheric humidity value is at or above the atmospheric humidity threshold or is outside a desired operating range of atmospheric humidity values), a rainwater intake value not satisfying the rainwater intake threshold (e.g., when the rainwater intake value is at or above the rainwater intake threshold or is outside a desired operating range of rainwater intake values), and/or a condensation value not satisfying a condensation threshold (e.g., when the condensation value is at or above the condensation threshold or is outside a desired operating range of condensation values).

[0069] Responsive to determining the presence of residual ignition energy in the ignition system 114, the controller 140 may provide an indication to a user. For example, the controller 140 may cause the operator I/O device 130 to display an indication of the presence of residual ignition energy in the ignition system 114. In some embodiments, the controller 140 may continue to the method 500 shown in FIG. 5.

[0070 [ FIG. 5 is a flow diagram of a method 500 of controlling one or more ignition systems 114 of the engine of FIG. 1, according to an example embodiment. In particular, the method 500 relates to controlling one or more of the ignition systems 114 to clear or discharge trapped residual ignition energy. In some embodiments, the controller 140 and/or one or more components thereof is/are configured to perform method 500. For example, the controller 140 may be structured to perform the method 500, alone or in combination with other devices such as the sensors 125 and/or other components of the system 100. In some embodiments, the processes of the method 500 may be performed in a different order than as shown in FIG. 5. In some embodiments, the method 500 may include more or fewer processes than as shown in FIG. 5. For example, processes 304, 306, and 308 may be optional and/or only for ignition systems 114 that include a dual coil. In some embodiments, the processes of the method 500 may be performed concurrently, partially concurrently, or sequentially.

[0071] Referring to the method 500 in more detail, at process 502 the controller 140 determines a residual ignition energy mitigation method. In some embodiments, the controller 140 may determine to use a residual ignition energy mitigation method based on whether the system 100 includes the appropriate hardware for performing the residual ignition energy mitigation method. That is, in some embodiments, the controller 140 may determine a residual ignition energy mitigation method based on receiving an indication of an available residual ignition energy. In a first example embodiment, the controller 140 may determine to use a residual ignition energy mitigation method specific to a dual coil ignition system responsive to receiving an indication that the ignition systems 114 includes a dual coil. In a second example embodiment, the controller 140 may determine to use a controlled leakage diode residual ignition energy mitigation responsive to receiving an indication that the ignition systems 114 includes a controlled leakage diode. In a third example embodiment, the controller 140 may determine to use a charge dump residual ignition energy mitigation responsive to receiving an indication that the ignition systems 114 includes a charge dump circuit. In some embodiments, one or more of the residual ignition energy mitigation methods are enabled without input from the controller 140. For example, the controlled leakage diode may passively (e.g., without input from the controller 140) provide an electrical pathway for the residual ignition energy.

[0072] In some embodiments, the controller 140 may determine a residual ignition energy mitigation method based on receiving an engine data. The engine data may include information about the engine 110, such as a number of cylinders 112, an engine displacement, a fuel type (e.g., hydrogen versus blended hydrogen), and/or other information related to the engine 110. For example, the controller 140 may determine to not use the stop restriking residual ignition energy mitigation method and/or the increase dwell time residual ignition energy mitigation method, responsive to receiving an indication that the fuel type of the engine 110 is a blended hydrogen fuel type and/or responsive to receiving an indication that the ignition system 114 does not include a dual coil ignition.

[0073] In some embodiments, when more than one residual ignition energy mitigation methods are available, the controller 140 may determine to use a residual ignition energy mitigation method based on a predetermined priority of each residual ignition energy mitigation method. In an example embodiment, the predetermined priority may include the controlled leakage residual ignition energy mitigation method first, the charge clearing discharge residual ignition energy mitigation method second, and the charge dump residual ignition energy mitigation method third. It should be understood that, in other embodiments, the predetermined priority of each residual ignition energy mitigation method may be different than as described herein.

[0074| In some embodiments, the controller 140 may determine to use a residual ignition energy mitigation method based on a predetermined priority of each residual ignition energy mitigation method relative to one or more operating parameters of the system 100. In some embodiments, the controller 140 may receive one or more parameters of the system 100. For example, the controller 140 may receive sensor data, engine operating conditions, and/or environmental conditions as described herein with respect to FIGS. 3 and 4. Additionally and/or alternatively, the controller 140 may receive data corresponding to the engine 110 (e.g., engine data) and/or corresponding one or more components of the system 100 downstream of the engine 110, such as a turbocharger (e.g., turbocharger data) and/or the aftertreatment system (e.g., aftertreatment system data). As described above, the engine data may include an engine fuel type, an engine displacement, a number of cylinders 112, etc. The turbocharger data may include a pressure change across the turbocharger, a turbocharger temperature value (e.g., a temperature of the turbocharger and/or a temperature of exhaust within the turbocharger, at an inlet of the turbocharger, at an outlet of the turbocharger, etc.), an exhaust flow rate (e.g., a mass or volumetric flow rate of exhaust through the turbocharger), and/or other data corresponding to the turbocharger. In some embodiments, the aftertreatment system data may include a temperature value (e.g., a temperature of one or more components of the aftertreatment system, a temperature of exhaust at within the aftertreatment system, at an inlet of the aftertreatment system, at an outlet of the aftertreatment system, etc.), a pressure value (e.g., a pressure change between an inlet and an outlet of the aftertreatment system, a pressure change across a component of the aftertreatment system, etc.), an exhaust flow rate (e.g., a mass or volumetric flow rate of exhaust through the aftertreatment system or through a component of the aftertreatment system), an aftertreatment system performance value (e.g., a change in concentration of one or more exhaust constituents, such as a change in nitrogen oxides, sulfur oxides, carbon oxides, etc.), and/or other data corresponding to the aftertreatment system. As briefly described above, any of the data received by the controller 140 may be detected or measured by a real sensor 125 and/or determined or estimated by a virtual sensor 125. In some embodiments, the controller 140 may determine to use a residual ignition energy mitigation method based on the received data and a corresponding, predetermined priority of each residual ignition energy mitigation method.

[0075] In some embodiments, one or more of residual ignition energy mitigation methods may be used concurrently, partially concurrently, or sequentially. In an example embodiment, the ignition system control residual ignition energy mitigation method may be used concurrently, partially concurrently, or sequentially with the charge dump residual ignition energy mitigation method. More specifically, the ignition system control residual ignition energy mitigation method may be used in combination with the charge dump residual ignition energy mitigation method responsive to receiving an indication that the fuel type is a pure hydrogen fuel. It should be understood that, in other embodiments, any combination of ignition energy mitigation methods may be used concurrently, partially concurrently, or sequentially.

[0076] At process 504, when the ignition system 114 is configured as a dual coil ignition system, the controller 140 may determine to use a residual ignition energy mitigation method specific to a dual coil ignition system. At process 506, the controller 140 may employ a stop restriking residual ignition energy mitigation method. At process 508, the controller 140 may employ an increase dwell time residual ignition energy mitigation method.

[0077] At process 510, the controller 140 may employ a charge clearing discharge residual ignition energy mitigation method. At process 512, the controller 140 may employ a controlled leakage residual ignition energy mitigation method. At process 514, the controller 140 may employ a charge dump residual ignition energy mitigation method.

[0078] At process 520, the controller 140 may employ an ignition system control residual ignition energy mitigation method. At process 520, responsive to employing the ignition system control residual ignition energy mitigation method, the controller 140 may receive ignition system data. At process 524, the controller 140 may adjust one or more ignition system parameters based on the ignition system data. For example, the controller 140 may adjust one or more of the spark timing, the spark energy, the spark duration, and/or the multi-spark capability of the ignition system 114 as described herein with respect to FIG. 2. [00791 FIG. 6 is a graph 600 depicting an air to fuel ratio (“X”) versus a minimum ignition energy (typically measured in millijoules (mJ). A first curve 602 represents the minimum ignition energy of various air to fuel ratios for a hydrocarbon fuel, such as methane. The second curve 604 represents the minimum ignition energy of various air to fuel ratios for a hydrogen fuel. A range of air to fuel ratio 606 is shown. A “stoic” air to fuel ratio refers to a stoichiometric mixture of air and fuel such that exactly enough air is provided to completely burn all the fuel. A stoic air to fuel ratio has a higher reactivity. That is, the stoic air to fuel ratio is easily ignited and has a lower minimum initial energy. The stoic air to fuel ratio may unintentionally combust due to an unintentional spark from residual ignition energy. A “lean” air to fuel ratio refers to air to fuel ratios less than the stoic ratio. The lean air to fuel ratio may have a higher minimum initial energy than the stoic ratio. However, the lean air to fuel ratio may result in a lower fuel economy (e.g., fuel consumption per mile).

[0080] Advantageously, the system and methods described herein mitigate residual ignition energy from being trapped in an ignition system of a hydrogen fueled engine. As described herein, in some embodiments, mitigating the residual ignition energy may include a “passive” method (e.g., a method that does not require action by a control system), such as a controlled leakage diode. In some embodiments, mitigating the residual ignition energy may include an “active” method (e.g., a method that does not require action by a control system), such as a charge clearing discharge, a charge dump, and/or an ignition system control method. In some embodiments, when an ignition system is configured as a dual coil ignition system, mitigating the residual ignition energy may include method(s) specific to a dual coil ignition system, such as a stop restriking residual ignition energy mitigation method and/or an increase dwell time residual ignition energy mitigation method.

|008.1] As utilized herein, the terms “approximately,” “about,” “substantially”, and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims.

[0082] It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

[00831 The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using one or more separate intervening members, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic. For example, circuit A communicably “coupled” to circuit B may signify that the circuit A communicates directly with circuit B (i.e., no intermediary) or communicates indirectly with circuit B (e.g., through one or more intermediaries).

[0084| References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below”) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.

[00851 While various circuits with particular functionality are shown in FIG. 2, it should be understood that the controller 140 may include any number of circuits for completing the functions described herein. For example, the activities and functionalities of the aftertreatment control circuit may be combined in multiple circuits or as a single circuit. Additional circuits with additional functionality may also be included. Further, the controller 140 may further control other activity beyond the scope of the present disclosure.

10086] As mentioned above and in one configuration, the “circuits” may be implemented in machine-readable medium for execution by various types of processors, such as the processor 204 of FIG. 2. Executable code may, for instance, comprise one or more physical or logical blocks of computer instructions, which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the circuit and achieve the stated purpose for the circuit. Indeed, a circuit of computer readable program code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices.

1 087] While the term “processor” is briefly defined above, the term “processor” and “processing circuit” are meant to be broadly interpreted. In some embodiments, the one or more processors may be external to the apparatus (e.g., on-board vehicle controller), for example the one or more processors may be or included with a remote processor (e.g., a cloud-based processor). In this regard, a given circuit or components thereof may be disposed locally (e.g., as part of a local server, a local computing system, etc.) or remotely (e.g., as part of a remote server such as a cloud-based server). To that end, a “circuit” as described herein may include components that are distributed across one or more locations.

[0088] Embodiments within the scope of the present disclosure include program products comprising computer or machine-readable media for carrying or having computer or machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a computer. The computer readable medium may be a tangible computer readable storage medium storing the computer readable program code. The computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable medium may include but are not limited to a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), an optical storage device, a magnetic storage device, a holographic storage medium, a micromechanical storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, and/or store computer readable program code for use by and/or in connection with an instruction execution system, apparatus, or device. Machine-executable instructions include, for example, instructions and data which cause a computer or processing machine to perform a certain function or group of functions.

[0089] The computer readable medium may also be a computer readable signal medium. A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electrical, electro-magnetic, magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport computer readable program code for use by or in connection with an instruction execution system, apparatus, or device. Computer readable program code embodied on a computer readable signal medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, Radio Frequency (RF), or the like, or any suitable combination of the foregoing.

[0090] In one embodiment, the computer readable medium may comprise a combination of one or more computer readable storage mediums and one or more computer readable signal mediums. For example, computer readable program code may be both propagated as an electro-magnetic signal through a fiber optic cable for execution by a processor and stored on RAM storage device for execution by the processor. [00911 Computer readable program code for carrying out operations for aspects of the present disclosure may be written in any combination of one or more other programming languages, including an object-oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program code may execute entirely on a local computer, partly on the local computer, as a standalone computer-readable package, partly on the local computer and partly on a remote computer, etc. In the latter scenario, the remote computer may be connected to the local computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0092| The program code may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks.

[0093[ Although the figures and description may illustrate a specific order of method steps, the order of such steps may differ from what is depicted and described, unless specified differently above. Also, two or more steps may be performed concurrently or with partial concurrence, unless specified differently above. Such variation may depend, for example, on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure.

(0094] It is important to note that the construction and arrangement of the apparatus and system as shown in the various exemplary embodiments is illustrative only. Additionally, any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein.

Claims

WHAT IS CLAIMED IS:

1. A method comprising: receiving data corresponding to an ignition system of at least one cylinder of a hydrogen fueled engine; determining, based on comparing the data to a first threshold, that residual ignition energy is present in the ignition system; and responsive to determining that the residual ignition energy is present in the ignition system, causing the ignition system to use at least one residual ignition energy mitigation process comprising at least one of a charge clearing discharge process, a controlled leakage event, or ceasing a restrike from the ignition system.

2. The method of claim 1, wherein the data comprises sensor data indicative of at least one of an engine torque, an engine exhaust manifold pressure, a cylinder pressure, or a cylinder ion value.

3. The method of claim 1, wherein the data comprises an engine operating parameter indicative of at least one of an engine speed or an engine load.

4. The method of claim 1, wherein the data comprises environmental data indicative of a humidity value.

5. The method of claim 1, wherein the at least one residual ignition energy mitigation process includes the controlled leakage event followed by one of the charge clearing discharge process or the ceasing of the restrike from the ignition system.

6. The method of claim 1, wherein the data includes information indicative of a load on the hydrogen fueled engine, the method further comprising: determining that the load is greater than a predefined high load threshold; and commanding the ignition system to implement the charge clearing discharge process.

7. A system comprising: an ignition system coupled to an engine; and a controller coupled to the ignition system, the controller comprising one or more processors and one or more memory devices storing instructions that, when executed by the one or more processors, cause the one or more processors to perform operations including: receiving data regarding at least one operating condition of the engine and data regarding at least one environmental condition regarding the system; comparing at least one of the data regarding the at least one operating condition of the engine to a first threshold or the data regarding the at least one environmental condition to a second threshold; determining that residual ignition energy is present in the ignition system based on at least one of: the data regarding the at least one operating condition of the engine is outside a first desired operating range, or the data regarding the at least one environmental condition is outside a second desired operating range; and responsive to determining that the residual ignition energy is present in the ignition system, causing the ignition system to implement at least one residual ignition energy mitigation process.

8. The system of claim 7, wherein the instructions, when executed by the one or more processors, further cause the one or more processors perform operations comprising comparing the at least one environmental condition to the second threshold responsive to determining that the at least one operating condition of the engine is outside the first desired operating range.

9. The system of claim 7, wherein the at least one operating condition of the engine includes an air-to-fuel ratio at a transient condition, and the first threshold includes an air- to-fuel ratio transient threshold.

10. The system of claim 9, wherein the at least one operating condition further includes a speed value of the engine, and the first threshold includes a low speed threshold.

11. The system of claim 9, wherein the at least one operating condition further includes a load value of the engine, and the first threshold includes a light load threshold.

12. The system of claim 7, wherein the at least one environmental condition includes at least one of an ambient humidity value, an ambient temperature value, or an indication that rainwater is entering an air intake system of the engine, and wherein the second threshold includes at least one of a humidity threshold corresponding to the ambient humidity value, a condensation threshold corresponding to the ambient temperature value, and a rainwater intake threshold corresponding to the indication that the rainwater is entering the air intake system of the engine.

13. The system of claim 7, wherein the at least one residual ignition energy mitigation process comprises at least one of a charge clearing discharge process, a controlled leakage event, or ceasing a restrike from the ignition system.

14. The system of claim 13, wherein: the ignition system includes dual coil ignition system; and the instructions, when executed by the one or more processors, further cause the one or more processors perform operations comprising at least one of: implementing a stop restriking residual ignition energy mitigation process, or implementing an increase dwell time residual ignition energy mitigation process.

15. The system of claim 7, wherein the instructions, when executed by the one or more processors, further cause the one or more processors perform operations comprising: receiving data regarding the ignition system; and adjusting one or more of a spark timing, a spark energy, a spark duration, or a multispark capability of the ignition system based on the data regarding the ignition system.

16. A non-transitory computer readable media comprising instructions stored thereon that, when executed by one or more processors of a processing circuit, cause the one or more processors to perform operations including: receiving data regarding an ignition system of a hydrogen fueled engine; determining that residual ignition energy is present in the ignition system based on comparing the data regarding the ignition system to a first threshold; and causing the ignition system to implement at least one residual ignition energy mitigation process responsive to determining that the residual ignition energy is present in the ignition system.

17. The non-transitory computer readable media of claim 16, wherein the at least one residual ignition energy mitigation process comprises at least one of a charge clearing discharge process, a controlled leakage event, or ceasing a restrike from the ignition system.

18. The non-transitory computer readable media of claim 17, wherein the at least one residual ignition energy mitigation process includes the controlled leakage event followed by at least one of the charge clearing discharge process or the ceasing of the restrike from the ignition system.

19. The non-transitory computer readable media of claim 16, wherein the at least one residual ignition energy mitigation process includes adjusting one or more of a spark timing, a spark energy, a spark duration, or a multi-spark capability of the ignition system based on the data regarding the ignition system.

20. The non-transitory computer readable media of claim 16, wherein the data regarding the ignition system includes information indicative of a load on the hydrogen fueled engine, and wherein the operations further include determining that the load is greater than a predefined high load threshold, and commanding the ignition system to implement a charge clearing discharge process.