Patent Description:
Generally, internal combustion (IC) engines are used in applications such as transportation, electricity generation, and the like. Unexpected breakdown of such engines hinders normal operations and adversely effects productivity. The IC engines are typically ignited using a spark produced by a spark plug. Spark plugs are vital for engine performance as the spark plugs provide sparks to ignite and burn the air-fuel mixture compressed in a cylinder of an IC engine. As will be appreciated, the spark plugs are parts that are subject to wear and tear and need to be serviced and replaced frequently. During replacement of a spark plug, an existing authentic spark plug needs to be replaced by another authentic spark plug. Replacing an authentic spark plug with a counterfeit spark plug adversely effects engine performance and may even cause irreversible damage to the engine. By way of example, installing a counterfeit spark plug may result in decreased efficiency, increased emissions from the engine, and the like.

Further, it is desirable to at least intermittently assess health of engines, to assist in diagnostics and/or prognostics of engine failures, and monitoring operations of the engines.

Known diagnostic methods for spark plugs are for example shown by <CIT>, <CIT> or <CIT>.

In one embodiment, a spark plug assembly according to claim <NUM> includes a spark plug, where the spark plug includes a high voltage connector disposed at one end of the spark plug and an insulator body having a first side and a second side. The insulator body is coupled to the high voltage connector at the first side. Further, the spark plug includes a metallic shell having a first side and a second side, where the first side of the metallic shell is coupled to the second side of the insulator body. The spark plug also includes an electrical conductor at least partly disposed in the insulator body and the metallic shell. The spark plug assembly includes a detection unit having a transmitter device and a receiver device. The transmitter device is coupled to the spark plug and is electrically disposed between the high voltage connector and the electrical conductor. The transmitter device is configured to draw an excitation current from the electrical conductor. The transmitter device includes an optical signal generator, where the optical signal generator is configured to generate an optical signal in response to the drawn excitation current. The receiver device is disposed in optical communication with the transmitter device and configured to receive the optical signal from the transmitter device.

In another embodiment, according to claim <NUM>, an engine includes one or more ignition modules, where each ignition module includes one or more ignition coils and one or more spark plug assemblies. The spark plug assemblies are coupled to respective ignition coils, where at least one of the one or more spark plug assemblies is according to claim <NUM>.

In yet another embodiment, a method according to claim <NUM> includes powering a transmitter device disposed in a spark plug using harvested energy from an electrical conductor of a spark plug. The method further includes transmitting an optical signal using the transmitter device, and receiving the optical signal using a receiver device, where the optical signal is representative of an identification parameter of the spark plug, or a diagnostic parameter of an engine, or both. The method also includes determining a control action based on the optical signal and initiating the control action for the engine.

In another embodiment according to claim <NUM>, a kit includes a detection unit, where the detection unit comprises a transmitter device and a receiver device. The transmitter device is configured to be coupled to a spark plug, where the transmitter device is configured to be electrically disposed between a high voltage connector and an electrical conductor. Further, the transmitter device includes an optical signal generator, where the optical signal generator is configured to generate an optical signal in response to the drawn excitation current. The receiver device is configured to be disposed in optical communication with the transmitter device. Further, the receiver device is configured to receive the optical signal from the transmitter device.

These and other features and aspects of embodiments of the invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:.

Embodiments of the present specification are directed to spark plug assemblies having a spark plug and a detection unit. The spark plug assemblies are configured to be used in engines. By way of example, the spark plug assemblies may be used in an internal combustion engine, a gas engine, or a gas turbine. In a spark plug assembly of the present specification, the detection unit in conjunction with the spark plug is configured to facilitate spark plug identification and/or engine monitoring. By way of example, the detection unit is configured to determine an identification parameter for the spark plug, a diagnostic parameter for an engine, or both. The identification parameter may correspond to a spark plug identification (ID), and the diagnostic parameter may correspond to diagnostic parameters of the engine. In certain embodiments, systems and methods of the spark plug assemblies may be used to determine spark plug specifics, such as, but not limited to, spark plug type, manufacturing date, manufacturer's name, and the like. In one example, the systems and methods of the spark plug assemblies may be used to determine the identification parameter to recognize and report use of a counterfeit spark plug in a spark plug assembly, or to determine use of an authentic spark plug in the spark plug assembly. Further, in some embodiments, the spark plug assembly may facilitate prognosis, diagnosis, or both of an engine in which it is employed. By way of example, one or more diagnostic parameters of the engine may be determined using the spark plug assembly. These diagnostic parameters may be used to prognose and/or diagnose the engine to schedule maintenance, determine leftover run time, determine replacement of certain parts of the engine, and the like.

<FIG> illustrates a portion of a spark plug assembly <NUM> of the present specification. The spark plug assembly <NUM> includes a spark plug <NUM> and a detection unit <NUM>. The spark plug <NUM> may be any spark plug that is suitable for use in a given engine. The spark plug <NUM> includes an insulator body <NUM> having a first side <NUM> and a second side <NUM>. The insulator body <NUM> is coupled to a high voltage connector <NUM> at the first side <NUM> of the insulator body <NUM>. The high voltage connector <NUM> is coupled to an ignition coil (not shown in <FIG>) of the engine, such as an internal combustion engine, a gas engine, or a gas turbine. The high voltage connector <NUM> is configured to connect to a high voltage source of the order of few KVs. The spark plug <NUM> also includes a metallic shell <NUM> having a first side <NUM> and a second side <NUM>, where the first side <NUM> of the metallic shell <NUM> is coupled to the second side <NUM> of the insulator body <NUM>. Further, the spark plug <NUM> includes an electrical conductor <NUM> at least partly disposed in the insulator body <NUM> and the metallic shell <NUM>. The electrical conductor <NUM> is disposed in a core of the spark plug <NUM> and extends along a longitudinal axis <NUM> of the spark plug <NUM>. The electrical conductor <NUM> is disposed between the high voltage connector <NUM> and a central electrode <NUM> of the spark plug <NUM>. Particularly, the electrical conductor <NUM> is housed in the insulator body <NUM> and the metallic shell <NUM> and is connected to the high voltage connector <NUM> at one end and the central electrode <NUM> at the other end.

The central electrode <NUM> includes an electrode tip <NUM>. Further, the spark plug <NUM> includes a ground electrode <NUM> having a ground electrode pad <NUM>. The ground electrode <NUM> is mounted on the metallic shell <NUM> using any suitable technique, such as welding. Moreover, the ground electrode pad <NUM> of the ground electrode <NUM> is disposed opposite to the electrode tip <NUM>. A gap, generally represented by reference numeral <NUM>, between the electrode tip <NUM> and the ground electrode pad <NUM> defines a spark gap. The spark gap <NUM> is the spacing between the electrode tip <NUM> of the central electrode <NUM> and the ground electrode pad <NUM> of the ground electrode <NUM>. The spark gap <NUM> may be measured and adjusted as required to facilitate generation of sparks to fire one or more cylinders in an engine.

The detection unit <NUM> is used for spark plug identification and/or engine monitoring. By way of example, the detection unit <NUM> may perform prognostics and/or diagnostics of an engine in which it is employed. The detection unit <NUM> includes a transmitter device <NUM> and a receiver device (not shown in <FIG>). The transmitter device <NUM> is coupled to the spark plug <NUM>. The receiver device is operatively coupled to the transmitter device <NUM> and disposed within or outside the engine. In embodiments where the receiver device is disposed within the engine, the receiver device may be disposed in a spark plug connector (as shown in <FIG>) or the receiver device may be disposed in an ignition coil of the engine (as shown in <FIG>). In other embodiments, the receiver device may be disposed in any other location in the engine where the receiver device may communicate with the transmitter device <NUM>.

The transmitter device <NUM> is electrically disposed between the high voltage connector <NUM> and the electrical conductor <NUM> of the spark plug <NUM> via internal electrical circuitry (not shown in <FIG>) of the spark plug <NUM>. The transmitter device <NUM> is configured to draw an excitation current from the electrical conductor <NUM>. The excitation current is used to ignite a spark in the spark plug <NUM>. Further, the transmitter device <NUM> includes an optical signal generator (not shown in <FIG>) configured to generate an optical signal in response to the drawn excitation current. The transmitter device <NUM> also includes a coder (not shown in <FIG>), such as a microcontroller, a field programmable gate array (FPGA), and the like. Further, the optical signal generator is configured to sustain high temperatures with minimal decrease in optical intensity at high temperatures. In some embodiments, the optical signal generator may include one or more light emitting diodes (LEDs). In certain embodiments, the light emitting diode (LED) may be a narrow view angle LED. In one embodiment, the LED may be an ultra-bright LED. In a non-limiting example, the LED may be a red LED, an orange LED, an ultra-bright red LED, an ultra-bright orange LED, or combinations thereof.

In some embodiments, the coder may have a relatively smaller footprint, which is suitable for employing the coder in the transmitter device <NUM>. Moreover, the coder may also have a suitable memory capacity appropriate for high temperature applications having a maximum temperature of <NUM>. A non-limiting example of the coder may include a peripheral interface controller (PIC).

<FIG> is a cross-sectional view of a portion of an engine <NUM> employing a spark plug assembly <NUM>, where the spark plug assembly <NUM> includes a spark plug <NUM> and a detection unit <NUM>. The detection unit <NUM> includes a transmitter device <NUM> and a receiver device <NUM>. The spark plug <NUM> is coupled to one end <NUM> of a spark plug connector <NUM>. The transmitter device <NUM> is disposed in the body of the spark plug <NUM>, while the receiver device <NUM> is disposed at another end <NUM> of the spark plug connector <NUM>. The spark plug connector <NUM> is an electrically insulated channel which is partly disposed in a spark plug sleeve <NUM>, which is a metallic sleeve.

While a side of the spark plug <NUM> having a high voltage connector (not shown in <FIG>) is disposed in a spark plug sleeve <NUM>, the other side of the spark plug <NUM> having the center and ground electrodes (not shown in <FIG>) is disposed in a combustion chamber <NUM> of the engine <NUM>. The spark plug sleeve <NUM> is electrically coupled to an ignition module (not shown in <FIG>). An ignition coil (not shown in <FIG>) is disposed between the ignition module and the high voltage connector (not shown in <FIG>) to connect the spark plug <NUM> to the ignition module. An electrical cable is disposed in the spark plug connector <NUM>. The ignition coil may be disposed in the spark plug connector <NUM>. In some embodiments, the spark plug connector <NUM>, which is an electrically insulated channel, may also be configured to act as an insulated optical conduit to communicate optical signals from the transmitter device <NUM> to the receiver device <NUM>. In other embodiments, the insulated optical conduit may be a separate element from the spark plug connector <NUM>. In some of these embodiments, the insulated optical conduit may be disposed inside the spark plug connector <NUM>. Additionally, although not illustrated, in some embodiments, an optical cable may be disposed in the spark plug connector <NUM> to provide optical communication between the transmitter device <NUM> and the receiver device <NUM>.

The engine <NUM> may further include one or more diagnostic sensors, such as sensors <NUM>. The diagnostic sensors <NUM> may be disposed in the ignition chamber <NUM> of the engine <NUM>. The diagnostic sensors <NUM> may be any suitable sensors that are able to withstand harsh engine environments. The diagnostic sensors <NUM> may be operatively and/or physically coupled to the transmitter device <NUM> of the detection unit <NUM>. In one example, the diagnostic sensors <NUM> may be physically wired to the transmitter device <NUM> using electrical cables. The diagnostic sensors <NUM> may include one or more of a temperature sensor, a pressure sensor, or a soot sensor. In certain embodiments, the diagnostic sensors <NUM> may include a negative temperature coefficient (NTC) sensor or a positive temperature coefficient (PTC) sensor. In some examples, the diagnostic sensors <NUM> may be a NTC or PTC thermistor. Further, the diagnostic sensors <NUM> may be coupled to the coder and configured to transmit an optical signal using the optical signal generator of the transmitter device <NUM>.

Additionally, the engine <NUM> may include an output unit <NUM> coupled to the spark plug assembly <NUM>. The output unit <NUM> is configured to receive an output signal from the receiver device <NUM>. The output unit <NUM> may include a display unit, a graphical user interface (GUI), or the like. In some embodiments, the output signal from the receiver device <NUM> and/or the output unit <NUM> may be communicated to an engine controller <NUM>. In some of these embodiments, the output unit <NUM> may be part of the engine controller <NUM>. Based on the output signal received from the receiver device <NUM>, the engine controller <NUM> may accordingly determine a control action, such as to generate an alarm, continue the operation as is, stall the operation, and the like.

<FIG> illustrates an engine <NUM> employing ignition modules <NUM>. The ignition modules <NUM> may be operatively coupled to form one or more banks. In the illustrated embodiment, the ignition modules <NUM> are shown to form two banks, referred generally to as a first bank <NUM> and a second bank <NUM>.

The ignition modules <NUM> of individual banks <NUM> and <NUM> are coupled using bridge modules <NUM>. The bridge module <NUM>, as the name suggests, bridges power and signal lines and provides a safety signal loop between the various ignition modules <NUM> of the engine <NUM>. In one example, the power lines may be configured to carry <NUM> V, and in same or different examples, the signal line may be a controller area network (CAN) bus. Further, the banks <NUM> and <NUM> may have connection modules <NUM> and end modules <NUM>. The connection modules <NUM> are configured to receive the power and signal lines for connecting to the ignition modules <NUM>, and the end modules are used to close the safety signal loop. Each ignition module <NUM> includes one or more ignition coils <NUM>. One or more ignition coils <NUM> in turn are coupled to respective spark plug assemblies <NUM>. The spark plug assemblies <NUM> include a spark plug (not shown in <FIG>) and a detection unit (not shown in <FIG>). A high voltage output of the ignition coil <NUM> is connected to the spark plug <NUM> using a high voltage connector (not shown in <FIG>) of the spark plug <NUM>. Although not illustrated, each ignition module <NUM> may include semiconductor bridges and at least one controller, where the controller may be configured to use a feedback mechanism to control a voltage applied to a corresponding ignition coil <NUM> to control the excitation current of an associated spark plug. The ignition module <NUM> may also house one or more relays or breakers to break a safety signal loop thereby powering down multiple ignition coils <NUM> to stop the ignition of the engine <NUM>.

The engine <NUM> includes an internal combustion engine, a gas engine, or a gas turbine. The internal combustion engine may be a vehicle engine. Non-limiting examples of vehicles may include a passenger vehicle, mass transit vehicle, military vehicle, construction vehicle, aircraft, watercraft, and the like.

The engine <NUM> further includes one or more engine controllers. In the illustrated embodiment, each individual bank <NUM> and <NUM> includes respective engine controllers <NUM> and <NUM>, respectively. The engine controllers <NUM> and <NUM> are configured to receive output signals from individual spark plug assemblies <NUM> and initiate a control action based on the received output signals. In some embodiments, the engine <NUM> may include a single engine controller for the banks <NUM> and <NUM>.

Referring now to <FIG> and <FIG>, alternative embodiments of spark plug assemblies are illustrated. A spark plug assembly <NUM> of <FIG> employs an insulated optical conduit for operatively coupling the transmitter and receiver devices, while a spark plug assembly <NUM> of <FIG> employs an optical cable for operatively coupling the transmitter and receiver devices.

<FIG> illustrates the spark plug assembly <NUM> having a spark plug <NUM> and a detection unit <NUM>. The detection unit <NUM> includes a transmitter device <NUM> and a receiver device <NUM>. The transmitter device <NUM> of the detection unit <NUM> is coupled to the spark plug <NUM>, and the receiver device <NUM> of the detection unit <NUM> is coupled to an ignition coil <NUM> and an ignition module <NUM> of an engine (not shown in <FIG>). The ignition coil <NUM> is coupled to the spark plug <NUM> via an electrical conductor <NUM>. The transmitter device <NUM> is coupled to the spark plug <NUM> such that the transmitter device <NUM> is electrically disposed between a high voltage connector (not shown in <FIG>) and the electrical conductor <NUM> of the spark plug <NUM>. Disposing the transmitter device <NUM> between the high voltage connector and the electrical conductor <NUM> enables the transmitter device <NUM> to draw an excitation current from the electrical conductor <NUM>. In addition to being configured to draw the excitation current from the electrical conductor <NUM>, the transmitter device <NUM> is also configured to generate optical signals in response to the drawn excitation current. The optical signals are generally represented by reference numeral <NUM>.

Although not illustrated in <FIG>, according to the invention, the transmitter device <NUM> includes an optical signal generator, a coder, and an energy storage device. Further, in certain embodiments, the transmitter device <NUM> includes a high temperature circuit board. In one example, the transmitter device <NUM> includes a high temperature printed circuit board (PCB). In a non-limiting example, the transmitter device <NUM> may include two or more optical signal generators or two or more energy storage devices. In a non-limiting example, the transmitter device <NUM> may employ two LEDs of different wavelengths as the optical signal generator.

In the illustrated embodiment of <FIG>, the transmitter device <NUM> and the receiver device <NUM> are held in operative and communicative association via an insulated optical conduit <NUM>. The insulated optical conduit <NUM> may also house the electrical conductor <NUM>. The insulated optical conduit <NUM> has a first end <NUM> and a second end <NUM>. The receiver device <NUM> may be disposed closer to the first end <NUM> of the insulated optical conduit <NUM>. In one example, the receiver device <NUM> may be at least partly disposed at the first end <NUM> of the insulated optical conduit <NUM>. Further, at the second end <NUM>, the insulated optical conduit <NUM> may be coupled to the transmitter device <NUM>. At least a portion of an internal surface <NUM> of the insulated optical conduit <NUM> is optically reflective. The insulated optical conduit <NUM> enables the optical signals <NUM> to traverse from the transmitter device <NUM> to the receiver device <NUM>. Specifically, the optically reflective internal surface <NUM> of the insulated optical conduit <NUM> facilitates traversal of the optical signals <NUM> from the transmitter device <NUM> toward the receiver device <NUM>.

The receiver device <NUM> includes an optical sensor <NUM>. The optical sensor <NUM> is coupled to a controller, generally represented by reference numeral <NUM>. The controller <NUM> may or may not be a part of the receiver device <NUM>. As illustrated in <FIG>, in some embodiments, the optical sensor <NUM> is disposed in the ignition coil <NUM>. In some of these embodiments, the optical sensor <NUM> of the receiver device <NUM> may be coupled to the transmitter device, such as the transmitter device <NUM>, using an optical cable (not shown in <FIG>). Further, the controller <NUM> may be a decoder, a microcontroller, an engine controller, or combinations thereof. In embodiments where the controller <NUM> is a microcontroller or a decoder, the controller <NUM> may be part of the receiver device <NUM> or the engine controller. Moreover, when deployed, the decoder or the microcontroller may be coupled to and in communication with the engine controller of the engine.

Turning now to <FIG>, a spark plug assembly <NUM> includes a spark plug <NUM> and a detection unit <NUM>. The detection unit <NUM> includes a transmitter device <NUM> and a receiver device <NUM>. An ignition coil <NUM> of an engine is coupled to the spark plug <NUM> using an electrical conductor <NUM>. The electrical conductor <NUM> is also coupled to the transmitter device <NUM>. Further, in the illustrated embodiment, the transmitter device <NUM> is coupled to the receiver device <NUM> using an optical cable <NUM>. The transmitter device <NUM> includes an optical signal generator <NUM>, a coder <NUM>, and an energy storage device <NUM>. According to the invention, the energy storage device <NUM> is coupled to the coder <NUM>, and the coder <NUM> in turn is coupled to the optical signal generator <NUM>. The voltage limiting device, such as a Zener diode <NUM>, is used to limit the voltage across the energy storage device <NUM> and bypass the excitation current when a determined voltage limit is achieved across the energy storage device <NUM>. The transmitter device <NUM> is configured to draw the excitation current from the electrical conductor <NUM>. The excitation current may be drawn by the transmitter device <NUM> from the electrical conductor <NUM> at regular intervals or irregular intervals. In some embodiments, the step of drawing the excitation current may be synchronized with spark events of the engine. In some other embodiments, the step of drawing the current may not be dependent on the spark events. The energy storage device <NUM> stores energy obtained from the drawn excitation current. Based on an identification parameter and/or diagnostic parameters, the coder <NUM> is configured to excite the optical signal generator <NUM> using the energy stored in the energy storage device <NUM>. Upon excitation, the optical signal generator <NUM> generates optical signals <NUM> representative of the identification parameter and/or diagnostic parameters. Diagnostic sensors from the engine (not shown in <FIG>) may be coupled to the coder <NUM> for optically transmitting the diagnostic parameters. The optical signals <NUM> are communicated from the transmitter device <NUM> to an optical sensor <NUM> of the receiver device <NUM> using the optical cable <NUM>. The optical signals <NUM> may be transmitted at pre-defined, frequent, regular, or irregular intervals. The optical cable <NUM> is selected based on for example, a wavelength of the optical signals <NUM>. In one embodiment, the controller represented by reference numeral <NUM> may be a part of the receiver device <NUM>. By way of example, the controller <NUM> may be a decoder that together with the optical sensor <NUM> may form the receiver device <NUM>. In another embodiment, the controller <NUM> may be an engine controller.

In certain embodiments, the detection unit, such as the detection unit <NUM> of <FIG>, detection unit <NUM> of <FIG>, detection unit <NUM> of <FIG>, detection unit <NUM> of <FIG> may form a kit. The kit may be retrofitted in existing engines or may be installed in newly manufactured engines or spark plugs. By way of example, the kit may be installed in an engine by a service provider when the engine is brought in for servicing. In another example, the detection unit may be factory fitted in an engine during or after manufacturing and/or assembling of the engine. The kit having the detection unit includes a transmitter device configured to be coupled to a spark plug, where the transmitter device is configured to be electrically disposed between an electrical conductor and a high voltage connector. Further, the transmitter device is configured to generate an optical signal in response to the drawn excitation current.

<FIG> is a flow chart <NUM> for a method for identification of a spark plug and/or for monitoring operation of an engine. The method of the flow chart <NUM> may be used for generating a control action based on an identification parameter of the spark plug, or a diagnostic parameter of an engine, or both. The identification and/or diagnostic parameters are determined based on an optical signal received from a spark plug assembly.

At step <NUM>, a transmitter device disposed in the spark plug of the spark plug assembly is powered using a portion of an excitation current. The excitation current is the electrical current that is used to ignite a spark in the spark plug. In some embodiments, a portion of the excitation current being carried by an electrical conductor of the spark plug is drawn or harvested by the transmitter device. The harvested electrical energy is used to power the transmitter device. Specifically, the drawn excitation current is used to charge an energy storage device of the transmitter device. Subsequently, the energy stored in the energy storage device is used by a coder of the transmitter device to excite an optical signal generator of the transmitter device to generate optical signals representative of identification and/or diagnostic parameters. Particularly, a determined amount of current is drawn from the energy storage device by the coder to excite the optical signal generator to generate an optical signal representative of the identification and/or diagnostic parameters.

In certain embodiments, the step of drawing the portion of the excitation current is synchronized with the spark events of an engine. In these embodiments, the identification parameter, diagnostic parameter, or both may be monitored during the spark events. In certain other embodiments, the step of drawing the portion of the excitation current is performed independent of the spark events of the engine. In some of these embodiments, the diagnostic parameters of the engine may be determined using one or more electrical parameters. In one example, a voltage may be sensed across a diagnostic sensor, such as, but not limited to, a NTC or PTC sensor, an analog or digitized value, of the voltage may be communicated to the receiver device via the transmitter device. Digitization of the analog value may be performed by a coder. Further, a table, such as a look-up table, may be used to determine a relation between the sensed voltage and one or more diagnostic parameters, such as a voltage, temperature, and the like.

At step <NUM>, an optical signal is generated using the coder and the optical signal generator of the transmitter device. Further, the optical signal is transmitted using the transmitter device and one or both of an insulated optical conduit or an optical cable.

Further, at step <NUM>, the optical signal is received using a receiver device, where the optical signal is representative of an identification parameter of the spark plug, or a diagnostic parameter of an engine, or both. The identification parameter of the spark plug is generally representative of the identification number of the spark plug. The diagnostic parameter of the engine is representative of one or more of a temperature, pressure, or soot composition.

At step <NUM>, a control action is determined based on the optical signal and the control action is initiated for the engine based on the identification parameter, diagnostic parameter, or both. In some embodiments, the diagnostic parameters may be provided as an input to the engine controller and based on the diagnostic parameters the engine controller may determine the control action. Non-limiting examples of the control action may include generating an alarm signal, shutting down the engine, maintaining status quo, such as for example, continuing to power the engine or run the engine, predicting health of the engine, scheduling maintenance of the engine, or combinations thereof. By way of example, an alarm may be generated based on the identification parameter, diagnostic parameter, or both.

In some embodiments, initiating the control action may include logging in the identification parameter of the spark plug in an engine data log registry, and continuing or discontinuing engine operations accordingly. In same or different embodiments, initiating the control action may include logging in the identification parameter of the spark plug in an engine data log registry. In instances where the spark plug is not a valid spark plug, the log entry may be a blank registry. An entry may be made in the engine log registry for every instance when the engine is started. In certain embodiments, initiating the control action may include displaying or communicating the identification parameter, diagnostic parameters, or both to an output device and/or the engine controller.

Claim 1:
A spark plug assembly, comprising:
a spark plug (<NUM>, <NUM>, <NUM>), wherein the spark plug (<NUM>, <NUM>, <NUM>) comprises:
a high voltage connector (<NUM>) disposed at one end of the spark plug (<NUM>, <NUM>, <NUM>);
an insulator body (<NUM>) having a first side (<NUM>) and a second side (<NUM>), wherein the insulator body (<NUM>) is coupled to the high voltage connector (<NUM>) at the first side (<NUM>);
a metallic shell (<NUM>) having a first side (<NUM>) and a second side (<NUM>), wherein the first side (<NUM>) of the metallic shell (<NUM>) is coupled to the second side (<NUM>) of the insulator body (<NUM>);
an electrical conductor (<NUM>, <NUM>, <NUM>) at least partly disposed in the insulator body (<NUM>) and the metallic shell (<NUM>);
a detection unit (<NUM>, <NUM>, <NUM>, <NUM>), comprising:
a transmitter device (<NUM>, <NUM>, <NUM>, <NUM>) coupled to the spark plug (<NUM>, <NUM>, <NUM>) and electrically disposed between the high voltage connector (<NUM>) and the electrical conductor (<NUM>, <NUM>, <NUM>), wherein the transmitter device (<NUM>, <NUM>, <NUM>, <NUM>) is configured to draw an excitation current from the electrical conductor (<NUM>, <NUM>, <NUM>), and wherein the transmitter device (<NUM>, <NUM>, <NUM>, <NUM>) comprises an optical signal generator (<NUM>), wherein the optical signal generator (<NUM>) is configured to generate an optical signal being representative of an identification parameter of the spark plug (<NUM>, <NUM>, <NUM>) and/or a diagnostic parameter of an engine (<NUM>, <NUM>) in response to the drawn excitation current, wherein the transmitter device (<NUM>, <NUM>, <NUM>, <NUM>) further comprises a coder (<NUM>) and an energy storage device (<NUM>) and wherein the energy storage device (<NUM>) is coupled to the coder (<NUM>) and the coder (<NUM>) is coupled to the optical signal generator (<NUM>); and
a receiver device (<NUM>, <NUM>, <NUM>) disposed in optical communication with the transmitter device (<NUM>, <NUM>, <NUM>, <NUM>) and configured to receive the optical signal from the transmitter device (<NUM>, <NUM>, <NUM>, <NUM>).